Solar energy


Last updated October 20, 2017

 

 

Home
Family
Fitness
    Nutrition
    Training
Friends
Homesteading     Bees
    Chickens
    Composting
    Geothermal
    Solar PV
    Solar Thermal
Humor
Martial Arts
Mathematics
Misc. Links
Movies
Music
Nostalgia
Outdoors
    Bicycling
    Hiking
    Kayaking
    Tubing
    Winter
Saki-ism
USMC

 

 

 
Selecting companies | Roof work | Solar work | Generating electricity, saving money, and journal | Future | Solar hot water heating


When Norma and I first saw our future house in Savage, Maryland, one of the first things we noticed was the south facing garage roof which was unobstructed by trees. "Wouldn't that be a nice place to put solar panels?"

About 7 months after purchasing the house, I started looking into this more seriously. At a local environmental meeting, I met someone from my old gym who owned his own solar company. He gave me his card. I also spoke to our neighbors, Don and Sara, who showed me the photovoltaic (PV) panels and microinverters they had installed. Photovoltaic means the panels are used to generate electricity, as compared to thermal which is used to generate heat. They recommended a couple of companies to me. I also got a recommendation for a roofer from Ralph. I now had enough information to get started and the motivation to get the ball rolling.

In our first year, we used about 9716 kilowatt hours (810 per month, 26.6 per day). It is estimated that high efficiency solar panels covering the south side of the garage could reduce our electricity consumption by 48%! Based on electricity costing $0.119 per kilowatt hour in November 2010, solar panels should reduce our electric bill by $568 per year. Note that we have oil heat and use electricity for our hot water heater and stove/oven.


Selecting companies

When it comes to making a big purchase, I almost never check with just one company. So I interviewed salespeople from three companies. I also tried to contact a fourth but they were too slow to respond. Of the three, I went with Solar Energy World.

Having the right salesperson really makes a big difference. At Solar Energy World, I was first contacted by Geoff Mirkin, the vice president. Then I spoke to Brent Cotton, a man who could sell freezers to Eskimos. Of the three salespersons I spoke to, all were friendly, professional, and knowledgeable. But Brent was best able to communicate his knowledge. Maybe it is because he has an engineering background and I have a math background. I almost felt like his talent was being wasted talking to just me...he should have been lecturing to a few hundred people in an auditorium.

But still, I am not one to just let a good salesperson sway me. I followed up with what he said, doing a little research on my own. The other companies wanted to sell me microinverters. I heard and read good things about microinverters. But Brent was the only one who told me I didn't need them. When a salesman tries to SAVE me money, my ears perk up. I spent a good deal of time investigating why microinverters are needed. For many situations, they are ideal...particularly in less than ideal situation, like when some panels get shade while others get sun. But my situation was a little different. The south side of my garage roof had no nearby trees to provide shade. The panels would be 20 degrees off due south according to Google Maps (azimuth 160 degree) and the solar access would be 98%. Additionally, if I went with Brent's suggestions, I would be buying the SunPower 230 monocrystalline photovoltaic solar panels. With 18.5% efficiency, these are the Cadillacs of the photovoltaic world (as of 2010). While most of what I read supported the use of microinverters, I decided to contact SunPower, explain to them my situation, and ask them for a recommendation. Their answer was almost the same as Brent's. Hence, I went with Solar Energy World.

Solar Energy World has a good reputation. They have an "A-" rating with the Better Business Bureau (as of November 2010). They also provided me with a list of references. I was confident I made the right choice.

But there was another consideration...my garage roof. When we bought the house in December 2009, we knew the garage roof was in need of work. It bowed in the center. There was no way I was going to spend thousands of dollars on solar panels and put them on a weak roof. It needed structural work. So I had to select a roofer. But while solar companies were more than willing to try and sell me their services, the same was not true of roofers.

In addition to Ralph's recommendation, I got several from the solar companies. A couple only did shingle work, not structural repair. Another was too busy to take on another job. A fourth said he would get back to me and never did. A fifth was just slow in getting back to me. With no real competition, I ended up going with Ralph's roofer, Adriano Candido.


Roof work


Adriano made a great impression. I climbed up on the roof with him and he gently peeled back some shingles. He showed me where the plywood beneath didn't reach all the way to cover the fascia in one place and how the fascia was thus rotting. He pointed out how the top support beam was a weak 2x8 board and how the 2x4 cross beams sometimes didn't reach all the way to the wall. Because the roof bowed, the south wall was pushed out a few inches. I told him that the roof would need to be strong enough to support 16 solar panels and mounting hardware, or 4 pounds per square foot. He suggested that the bowed 2x8 beam be replaced by an LVL laminated beam. Some of the cross beams should also be replaced by LVL beams. He would push the south wall back in, replace the fascia with PVC board, and replace the plywood with 5/8th of an inch thick plywood (extra thick for roofs).

I did some research about LVLs. Indeed, they are extremely strong and specifically made for supporting heavy loads. It sounds like they are the next best thing to steel when it comes to home construction, and in some ways, more environmentally friendly.

Hoping to be able to write off some of the cost of a new roof on my taxes, I wrote up a little statement for Adriano to sign. It basically said that in his professional opinion, the work he was doing on my garage was necessary to ensure it would safely support the weight of solar panels. This was indeed the case.

In October 2010, Adriano and his crew of 3 spent about a week taking off the old roof, removing beams, installing new beams, installing new plywood, putting on new fascia, and installing a new roof. He actually did much more than this and I am just mentioning the highlights. See the photos at left.

I was pleased with Adriano's work.

For me, the garage is my man-cave. I store my kayaks, tools, and weights there. It is my workshop and gym. So while spending $9650 to get it fixed up may sounds expensive, I am more than confident it will now support the solar panels soundly and will last for decades to come.


Solar work





Garage panels

After the work on the garage was complete in the fall of 2010, I signed a contract with Solar Energy World to get the panels installed. From here on out, I mainly worked with Danny Polk to get appointments scheduled.

I paid Solar Energy World a total of $24,485 for the 16 panels, inverter, and installation.

First, a Howard County inspector had to come out, inspect things, then grant a Residential Building Permit and Residential Electrical Permit.

Then, a significant amount of paperwork needed to be completed. This is where it pays to hire a company that knows their stuff. With federal, state, county, and Solar Renewable Energy Credits (SRECs) helping out, I can get 63% of my initial investment returned just from these sources...that is, if the paperwork is filled out and submitted properly. These are the forms I filled out:
  • Maryland Solar Energy Grant Program, Photovoltaic Solar Grant
  • Maryland Solar Energy Grant Program Terms and Conditions
  • Pre-Qualification Form, Maryland Solar Energy Grant Program
  • Photovoltaic Solar Grant Application Form, Maryland Solar Energy Grant Program
  • Interconnection Agreement Certificate of Completion
  • Interconnection Request Application Form and Conditional Agreement to Interconnect
  • Energy Conservation Device, Solar Heating or Electric Production Certification Form
  • SRECTrade: EasyREC Enrollment Form

  • There were some problems when submitting paperwork to the Maryland Energy Administration. They returned my application more than once, saying it was incomplete. Apparently, they changed the forms without passing this information onto the solar companies. Kathryn and Jennifer helped me out with resubmitting the forms. These are the forms that must be received before I can be issued a state certification number generated by the Maryland Public Service Commission. The state certification number is needed prior to enrollment in SRECTrade.

    It took only a half day for guys to come out and install the panels on November 29, 2010. See first and second photos at left. The brackets attach directly to the trusses so I suppose the extra thick plywood on the roof wasn't necessary.

    On November 30, Phet and Mel installed the central inverter, a SunPower SPR-3000m. See third and fourth photos. This is what converts the direct current (DC) power generated by the panels into alternating current (AC). According to the electrical data on the information sheet, the recommended array input power is 3600 watts. With my 16 panels, each capable of generating 230 watts, the total maximum wattage is 3680. This had me a little concerned but Jason Chretien, the Solar Energy World engineer, assured me that
    the "230" is the standard test conditions STC rating of the panels. The performance test condition ratings of the panels are slightly less than that, so we can actually fit more STC than stated on the spec sheet. We actually have your system sized to 98%.
    I also checked with SunPower, and their reply was
    No need to be concerned on this. The 3,600W is a mere recommendation it can go over on under this value. The 3680 is the STC rating and does not signify the actual wattage being as input to the inverter. Considering all derating for solar, the approximate input wattage in to your inverter would be 3680 x 0.77 (General Derating for Solar) = 2,833 watts ready for conversion to AC Power by the inverter. So you should be Ok.

    On December 7, someone from the county came out to inspect the electrical work done by Solar Energy World. Immediately after passing inspection, the system was activated.

    On December 20, a guy from the power company came out and replaced my electric meter with a new one. This new net meter runs backwards as well as forward. Hence, if my panels generate more energy than we use (as would be expected on a sunny day when we're not home), excess electricity will be fed back into the grid and our net meter will run backwards.

    On January 5, I was given a written notice of final approval for my application for a level 1 interconnection from Baltimore Gas and Electric (BGE).

    On January 10, Jason set me up with a SunPower web page from which I could monitor my solar energy generation. This information is transmitted from my system to the internet via a SunPower Monitoring System Gateway (model SPR-PMR-GTWY). It all seemed pretty simple. See fifth image. On the right side of the page was the total energy output over the lifetime of the panels. On the left side was energy output over a given window of time. I did a little sanity check to make sure that the cumulative total over the dates since the installation of the panels matched the value on the right side of the page. It did not. It wasn't even close. So I contacted Solar Energy World to inquire. I was told the following:
    I have no idea what has caused the difference, I just know that the box on the right hand side is taken directly from the inverter. The graph is collected from the monitoring system. You can check the production meter to verify what the system has generated.
    I was a little surprised I wasn't instead told, "We don't know but will find out and get back to you with an answer." That is how I was taught to reply to a customer when I didn't have an answer. So I contacted SunPower directly. As usual, they were prompt and thorough with their reply:
    I found out that there seems to be frequent disconnections on your SunPower Gateway. That could be a reason for lost data. This means that not all data is being monitored because of the frequent disconnections. We suggest for you to keep your gateway or your internet ON especially during the day while the inverter is operating for us to avoid loss of data.
    That was the answer I sought. I turn off my modem and SunPower gateway at the power strip to conserve energy. I didn't think that data would not be stored and transmitted once the gateway was turned on. So now I know what to do differently. All is good.

    Around January 23, my SunPower wireless display stopped showing how much energy my panels were producing. But the SunPower gateway still worked and I confirmed that it was successfully transmitting my energy generation stats to my modem. The wireless display would still light up when the button was pressed, indicating that the batteries still had energy. But it turned out that the batteries did not have enough energy to receive signals from the gateway. So a fresh set of 4 AAA batteries fixed this problem.

    On March 29, 2011, Eric Mooney told me that my account was set up for SREC Trade.

    On July 8, 2011, I finally received my Maryland Solar Energy Grant money.














    House panels

    In the spring of 2013, I decided to get a solar thermal hot water heater. This was put on my house, not my garage.

    Since I don't believe in getting new solar panels put on a 20+ year old roof, I got a new roof. The solar thermal panels went on the south side. I decided to get more photovoltaic panels on the west side. My goal is to be net zero or as close to that as possible.

    For the additional photovoltaic panels, I interviewed many of the same companies I interviewed for my solar thermal hot water heater since these companies did both types of installation. I also re-interviewed Astra. But in the end, Solar Energy World got my business again. So on May 21, 2013, I signed a contract to get 10 Suniva Optimus OPT260-60-4-1B0 260 watt monocrystalline solar photovoltaic panels for a total cost of $10,140. This includes installation and central inverters.

    Originally, I thought we would go with microinverters since the west side of the roof on my house gets partial sunlight blockage from trees late in the day. But Brent felt that central inverters would be better since we were still going with only one roof surface. That is, if the panels were spread out between the west and the south sides of my roof, then microinverters would be a better choice. Additionally, for these particular panels, the central inverter would also be better because the Enphase microinverter has a 215 watt maximum capacity which means we would be "clipping" power. For this case, the central inverter ensures optimal output.

    These panels face west by southwest, having an azimuth of 248 degrees. The roof has a slope of 27 degrees. Annual output should be 3131 kwh/year. This factors in the fact that we have 89% solar access on the west roof, where they will be installed. This is nowhere as good as our south roof which has 100% or darn near close to that amount. This much energy generation means we should save money in the following ways:
  • Federal tax credit: $3042
  • Maryland Energy Grant: $1000; this was later denied.
  • Avoided electric costs per year: $350 based on June 2013 rates with Castlebridge ($0.111669 per kWh after taxes and fees).
  • SRECs: This amount fluctuates and will almost certainly go down over time. If my annual output is 3131 kwh, then I will generate 3131/1000 = 3.131 SRECs per year. For 12 SRECs generated from December 7, 2010 to August 29, 2013, I earned $1094.54 + $252.96 = $1347.50 which averages out to $112.29 per SREC. If SRECs become worthless, I get nothing. And if they maintain their same rate, I get 3.131 * $112.29 = $351.58 per year for the sale of SRECs. Realistically, what I actually get will be between zero and $351.58, probably leaning towards the latter.

  • This being the case, the system should pay for itself somewhere between ($10,140 - $3042)/($350 + $351.58) = 10.12 years and ($10,140 - $3042)/$350 = 20.28 years, depending on how well SRECs maintain their value. Brent expects I will get back more on SRECs and avoided electric costs so he is estimating the system will pay for itself in 7.2 years. Regardless, it is much harder to justify the purchase of photovoltaic solar panels without the Howard County tax credit that was in place when I purchased my first set of panels.

    On June 3, 2013, James Carpenter came by to do a solar site assessment.

    Later that month, Jason Chretien sent me a proposed layout for the panels. It wasn't at all what I wanted. The original drawing that Brent provided and we discussed would have all 10 shifted as far as possible to the south side on the west roof of the house. This would allow Norma and me to grow a tree on the north half of the west side of the house without having to worry about shade from the tree getting in the way of the panels. The drawing I received on June 20, showed the panels much further to the north side than what was discussed. Jason revised the drawing but said that in order to get the panels further south, they would need to remove one of our roof ventilation pipes and attic fan. That was unacceptable. After some discussion, we came up with the configuration shown in the first image. The amount of sunlight at each position is illustrated in the second image. The expected electricity generation is listed in the third image. This turned out to be a little less than I expected (3062.7 kWh instead of 3131 kWh) though only by 2%.

    The actual installation was done in half a day on July 19, 2013. A fellow by the name of Mark was in charge. He installed what they gave him which was 10 Suniva 265 panels with the silver edges. I was expecting the all black panels but the silver edges were fine and hardly visible except except from much much further back in my yard. The silver edge panels actually have better output than the 260s that I expected so it all worked out fine in the end. See fourth photo.

    Mark's team also installed the Power One PVI-3.0-OUTD-S-US Aurora String Inverter 3000 Watt central inverter on the west side of my house at the south end. See fifth and sixth photos. Just below this was the electrical disconnect and production meter. See seventh photo. This was placed next to the disconnect for the panels on my garage. Such disconnects are required by law to be accessible outside the house so the utility company can shut off my system when they work on the power lines. This protects the utility workers.

    Inside the house, an electrical conduit was run from the panels to my attic (eighth photo) and then from the attic to a line outside the house (ninth photo). This line ran to the breaker panel in my basement. See tenth photo for my breaker configuration (this changed in December 2013). Next to the breaker panel was the solar monitoring box which contains hardware for measuring output. See eleventh photo. This data is sent to my modem via a gateway device (twelfth photo). The information is sent to a web page where I can then monitor production.

    On August 8, 2013, Keith Roycroft of Solar Energy World came by to meet the county inspectors and turn on my system. So as of August 8, 2013 my newer set of solar photovoltaic panels are operational.

    I was set up with a web page where I can view the amount of energy my system generated. According to the thirteenth photo, my 2.65 kW Suniva system produced 15.52 kWh of electricity as of the close of August 9, 2013. Just for that day, it produced 7.66 kWh. This compares with 13.3 kWh produced on the same day by my SunPower system on the garage. I have 16 panels on the garage that comprise a 3.68 kW system. All things being equal, I would expect 13.3 x (2.65/3.68) = 9.57 kWh of electricity. But of course, all things are not equal. The panels on the house face west and do not get nearly as much sunlight as the panels on the garage. As I mentioned earlier, the garage panels have 100% solar access or near that. Panels on the house have 89% access. So I should be getting 9.57 x 0.89 = 8.52 kWh of electricity. The difference, 8.52 - 7.66 = 0.86 kWh, is about 0.86/8.52 = 10% less than the expected amount. My new Suniva panels should generate (2.65/3.68) x 0.89 = 64% of the amount of electricity as the older SunPower panels on my garage.

    On August 13, 2013, I filled out and submitted forms so my SRECs from the new system will be managed by Sol Systems.

    On August 16, 2013, I received a new net meter. I'm not sure why the last one wasn't sufficient but maybe this new one is also a smart meter that the utility company uses to gather more information about usage. Anyway, that afternoon, I noticed that the reading was 99991, meaning that I produced 9 kwh more than I used.

    I observed over a few days that my Suniva panels' energy gathering drops off sharply around 1800. I'm guessing that is when the sun drops behind the trees on the west side of my house.

    Over 13 days from August 10 to August 23, 2013, my new Suniva panels generated 131.59 kWh, averaging 10.12 kWh per day. In comparison, my older SunPower panels generated 210 kWh over this same period. This means my Suniva panels produced 131.59/210 = 62.66% as much genergy as the SunPower panels. This is easily within ballpark range of my expectation, which is 64%.

    On August 29, 2013, I received word from the Maryland Energy Administration that my application for the $1000 energy grant was denied because I already have photovoltaic panels that I received grant money for two years ago.
    ...although the systems are on separate buildings and use different inverters they still both deliver electricity to your home, is that correct? If so, this would count as serving the same load, and would therefore not be eligible for another grant. If this second system serves an entirely different load, however, then it may still be eligible.

    I wasn't upset about the state denying my grant application. I didn't think it was eligible in the first place. What annoyed me is that Solar Energy World thought I could get the money in the first place, knowing that I received it in 2011. In fact, they built it into their return on investment calculation. Had I known this, I don't know if I would have gone ahead with the purchase. Still, they offered the most bang for the buck. I was later informed by Brent that as of 2013, the Maryland Energy Administration policy regarding the solar energy grant changed and his company was not fully informed of this change by the state. I have never known Brent to be one to be dishonest. In fact, there are two times I can think of when he turned down the opportunity to make more money off me because he felt it was in my best interest. So I give him and his company the benefit of doubt.

    On October 6, 2013, our house was recognized as one of 48 on the "4th Annual Maryland Tour of Solar and Green Homes." This means it was listed in a booklet and open to the public for the afternoon. What makes our home green? We use solar photovoltaic panels, solar thermal hot water heater, geothermal heat pump, rain barrels, extra insulation in the attic, composting, and a pellet stove which burns fuel made from sawdust and other wood waste. All this in a home built in 1952! The event was a success. I had about 25 attendees, mostly neighbors, co-workers, and kayakers, and there was never any down time. It lasted from 1100 to 1800.

    One question I get is what happens if I generate more electricity than I consume? Now that I have 26 panels, this is a common scenario.
    If the energy generated by the customer-generator exceeds the energy supplied by the utility during the month, the customer-generator shall be required to pay only the customer charges for that billing month, as required by the Rate Schedule under which the customer-generator is receiving service. The utility will carry forward a negative kilowatt-hour reading for a period not to exceed 12 months and that ends annually with the April bill. The utility will pay each eligible customer-generator for the dollar value of any accrued net excess generation remaining at the end of the previous 12 month period ending with the billing cycle that is complete immediately prior to the end of April.
    - from BGE - Common Questions and forwarded to me by Andre M. Unfortunately, this website no longer exists.

    As of 2015, I have not been able to carry forward a negative kilowatt-hour reading in April but my co-worker, Rod A. has. He was paid 11.29 cents per kilowatt-hour. It wasn't as much as he pays for kilowatt-hour but it isn't significantly less either.

    In January 2014, I learned that some people are having problems with squirrels chewing through the wires that connect to their solar panels.
  • Why squirrels are nuts about solar panels
  • Squirrels Under the Solar Panels
  • In battle with squirrels, solar panels finally claim victory

  • Generating electricity, saving money, and journal












    My 16 SunPower 230 watt photovoltaic solar panels installed in 2010 should produce up to 3.68 kilowatts and an estimated 4774 kilowatt hours (kWh) per year. This means it should produce an average of 13.08 kWh per day.

    Notice the nice Gaussian curve on the first image at the left. This is the histogram on my SunPower account monitoring page for solar energy generation for February 15, 2011.

    Let's see how it actually did by going back to when we first bought the house, a year prior to installing solar panels:

  • December 19, 2009 to January 14, 2010: 685 kWh
  • Purchased home on December 18, 2009.

  • January 14, 2010 to February 12, 2010: 619 kWh

  • February 12, 2010 to March 15, 2010: 1024 kWh

  • March 15, 2010 to April 15, 2010: 662 kWh

  • April 15, 2010 to May 14, 2010: 654 kWh

  • May 14, 2010 to June 15, 2010: 726 kWh

  • June 15, 2010 to July 15, 2010: 924 kWh

  • July 15, 2010 to August 16, 2010: 1115 kWh

  • August 16, 2010 to September 15, 2010: 759 kWh

  • September 15, 2010 to October 14, 2010: 548 kWh

  • October 14, 2010 to November 13, 2010: 613 kWh

  • November 13, 2010 to December 13, 2010: 648 kWh
  • On December 7, 6 kWh were generated. The system was turned on right after passing inspection, around noon.
    On December 8, 12 kWh were generated. It was sunny.
    On December 9, 14 kWh were generated. It was sunny. Energy production started at around 0730 with about 40 watts.
    On December 10, only 2 kWh were generated. It was very overcast.
    On December 11, 7 kWH were generated. This is the first day that the SunPower account monitoring page actually starts recording my electricity generation.

  • December 13, 2010 to January 14, 2011: billed for 407 kWh; 255 was generated by solar; total consumption = 662 kWh
  • On December 21, the winter solstice, 11.6 kilowatt hours were generated. This was the shortest day of the year. It was fairly sunny. I can hardly wait to see how my system performs on the long spring and summer days. The only disadvantage is that the inverter performs more efficiently in cold weather which could offset some of the benefits of the summer days.

    It was great showing my parents the panels during their December 16-21, 2010 visit. Unfortunately, they (the panels, not my parents) were covered with snow for the first few days. I noticed that my neighbors' panels had no snow on them while mine were still halfway covered. I attribute this to their roof being angled much more sharply than mine. Theirs is 45 degrees, which I believe is ideal. After the snow melted, we had no more precipitation for quite awhile. I noticed my panels were covered with a noticeable amount of dust. But they were still generating a good bit of power...just not as much as they could have. I suppose having a more steeply angled roof would help any precipitation to clean the panels more efficiently.

    December 20, 2010: New net meter installed that runs backwards when more power is generated than is consumed.

    In December 2010, my panels averaged 7.52 kWh per day, ending with a cumulative total of 187.97 kWh.

    On January 19, we received our first electric bill reflecting a full period for which the panels were present: December 13, 2010 to January 14, 2011. In the first 7 days, prior to installation of the new net-meter, we used an average of 11.86 kWh per day. In the remaining 24 days, we used an average of 13.5 kWh per day. I would have expected the second half to be less but that was not the case. Comparing this period with the same from last year gave some impressive results. Last year, the period was only 26 days because we had just moved in. The average temperature was 30 degrees. This year, the period was 32 days with an average temperature of 31 degrees. But temperature shouldn't matter much since we use oil heat. Last year at this same time, we averaged 26.3 kWh of electrical usage per day but this year, we averaged only 20.7 kWh.

    Another thing I did to save money was change electric providers. Despite having solar panels, we still need to buy electricity...so why pay more? After the utility companies were deregulated, customers had a choice. By default, we have BGE, who, as of January 2011, charges 10.029 cents per kWh. At a no-longer-existing website (as of 2016), once called Choice, several other providers are listed. I compared their rates and found Dominion to be the most competitive at 9.4 cents per kWh, which is much better than BGE's rate and future rate, which was listed at a website which no longer exists as of 20-16 called Supply Price Comparison Information. Hence, I switched both my Savage house and Hanover house to Dominion on January 29, 2011. Before getting solar panels, this would have saved us about $6.56 per month but with solar panels, we only save about half this amount. But my tenants at my Hanover house will save about $7.36 per month. We don't use natural gas but my tenants do, so I checked on this too. BGE charges 63.71 cents for the first 151 therms and 63.04 cents for additional therms (assuming I am reading the bill correctly). Their rate was the best. Dominion does not provide natural gas in my area. The other thing I read about was Peak Rewards, a program offered by BGE to reduce stress on the power grid when demand is greatest. Since my Savage home doesn't have central air, I can't take advantage of this, but my tenants in Hanover can.

    So how has this affected our bills? For our December 13, 2010 to January 14, 2011, we saved $22.24 thanks to solar power. Note that the new net meter wasn't installed until December 20. Naturally, had it been installed earlier, we would have saved more money.

    In January 2011, my panels generated 221 kWh, averaging 7.13 kWh per day, and ending with a cumulative total of 409 kWh.

  • January 14, 2011 to February 14, 2011: billed for 396 kWh; 257 kWh was generated by solar; total consumption = 653 kWh
  • My panels averaging 8.29 kWh per day during this billing period. Not terribly great but keep in mind that for almost a full week in late January there was snow on the roof so no energy was generated.

  • February 14, 2011 to March 14, 2011: billed for 252 kWh; 363 kWh generated by solar; total consumption = 615 kWh
  • I got my taxes done in early February. My accountant had no problem with including the cost of the work done on my garage roof with the solar panels. After all, my roof would not have been able to have safely held the panels without major structural work. Hence, I got a very large federal rebate.

    February 15, 2011 was a good winter day for solar generation. While the day was short, the sun was bright, and a good deal of energy was created. Notice how the histogram in the photo has a nice Gaussian shape. This is also a fine example of how my SunPower monitoring page displays output for a single day.

    In February 2011, my panels averaged 11.39 kWh per day, ending with a cumulative total of 730 kWh.

  • March 14, 2011 to April 14, 2011: billed for 229 kWh; 452 kWh generated by solar; total consumption = 681 kWh

  • In March 2011, my panels averaged 14.42 kWh per day, ending with a cumulative total of 1177 kWh.

  • April 14, 2011 to May 13, 2011: billed for 21 kWh; 479 kWh generated by solar (95.8%); total consumption = 500 kWh

  • Keep in mind that we were in Germany May 7-16, 2011.
    In April 2011, my panels averaged 14.53 kWh per day, ending with a cumulative total of 1613 kWh.

  • May 13, 2011 to June 16, 2011: billed for 116 kWh; 599 kWh generated by solar (84%); total consumption = 715 kWh

  • In May 2011, my panels averaged 16.87 kWh per day, ending with a cumulative total of 2136 kWh.

  • June 16, 2011 to July 16, 2011: billed for 154 kWh; 560 kWh generated by solar (78%); total consumption = 714 kWh

  • In June 2011, my panels averaged 18.23 kWh per day, ending with a cumulative total of 2683 kWh.

  • July 16, 2011 to August 12, 2011: billed for 213 kWh; 720 generated by solar (77%); total consumption = 933 kWh

  • In July 2011, my panels averaged 18.65 kWh per day, ending with a cumulative total of 3281 kWh.

  • August 12, 2011 to September 15, 2011: billed for 300 kWh; 761 generated by solar (61%); total consumption = 761 kWh

  • In August 2011, my panels averaged 15.45 kWh per day, ending with a cumulative total of 3760 kWh.

    In late August, we were faced with tropical storm Irene which brought intense wind and rain. A few weeks later, tropical storm Lee brought record-breaking rains. Check out the second image at left to see how this affected solar energy generation.

  • September 15, 2011 to October 15, 2011: billed for 310 kWh; 438 kWh generated by solar (59%); total consumption = 748 kWh

  • In September 2011, my panels averaged 9.73 kWh per day, ending with a cumulative total of 4073 kWh.

  • October 15, 2011 to November 12, 2011: billed for 149 kWh; 335 kWh generated by solar (69%); total consumption = 484 kWh

  • In October 2011, my panels averaged 11.38 kWh per day, ending with a cumulative total of 4426 kWh.

    Norma was in Europe for 10 days during this period and I hardly touched our electric stove during that time.

  • November 12 to December 12, 2011: billed for 248 kWh; 258 kWh generated by solar (51%); total consumption = 506 kWh

  • December 12, 2011 to January 14, 2012: billed for 290 kWh; 247 kWh generated by solar (46%); total consumption = 537 kWh

  • January 14, 2012 to March 14, 2012: billed for 413 kWh; 788 kWh generated by solar (66%); total consumption = 1201 kWh

  • March 14, 2012 to April 13, 2012: billed for 169 kWh; 466 kWh generated by solar (73%); total consumption = 635 kWh

  • April 13, 2012 to May 15, 2012: billed for 107 kWh; 503 kWh generated by solar (82%); total consumption = 610 kWh

  • May 15, 2012 to June 14, 2012: billed for 104 kWh; 551 kWh generated by solar (84%); total consumption = 655 kWh

  • June 14, 2012 to July 14, 2012: billed for 205 kWh; 544 kWh generated by solar (73%); total consumption = 749 kWh

  • July 14, 2012 to August 16, 2012: billed for 428 kWh; 531 kWh generated by solar (55%); total consumption = 959 kWh (it was really hot)

  • August 16, 2012 to September 15, 2012: billed for 177 kWh; 483 kWh generated by solar (73%); total consumption = 660 kWh

  • On September 20, 2012, I made the necessary phone calls and filled out paperwork to switch my energy provider from Dominion Energy to Castlebridge Energy Group. This reduced our electricity rate from 8.87 cents per kilowatt hour to 7.79. Of course Dominion had an introductory offer they wanted to extend to me but it wasn't as low as that of Castlebridge. I also switched my tenant's gas provider from BGE to Castlebridge, thereby reducing their rate from 56.63 cents per therm to 51. Overall, this means a 12% savings in electricity and a 10% savings in gas. This considers only electricity and gas, not fees or taxes.

  • September 15, 2012 to October 15, 2012: billed for 233 kWh; 409 kWh generated by solar (64%); total consumption = 642 kWh

  • October 15, 2012 to November 13, 2012: billed for 278 kWh; 294 kWh generated by solar (51%); total consumption = 572 kWh

  • November 13, 2012 to December 12, 2012: billed for 476 kWh; 263 kWh generated by solar (35%); total consumption = 741 kWh

  • On November 15, 2012, a geothermal heat pump was turned on in my house. This means that instead of oil providing a majority of the heating, a high efficiency electric system was used. This explains the significant increase in electricity use in the November 13, 2012 to December 12, 2012 time period and thereafter during the winter. For more information, see Heating.

  • December 12, 2012 to January 14, 2013: billed for 648 kWh; 238 kWh generated by solar (27%); total consumption = 886 kWh

  • January 14, 2013 to February 13, 2013: billed for 635 kWh; 245 kWh generated by solar (28%); total consumption = 880 kWh

  • In March 2013, I canceled my SREC Trade account and switched to Sol Systems at the suggestion of a neighbor. I set up this account through Solar Energy World. Basically, SolSystems handles my SRECs and sells them when they think they can get a good price. In turn, they get a commission of the profit.

  • February 13, 2013 to March 14, 2013: billed for 603 kWh; 362 kWh generated by solar (38%); total consumption = 965 kWh

  • March 14, 2013 to April 12, 2013: billed for 273 kWh; 456 kWh generated by solar (63%); total consumption = 729 kWh

  • On May 28, 2013, I received $1094.54 from SolSystems for selling 10 SRECs. Four were sold for $95 each while six were sold for $119.59 each. This seems very low but I've been told that the prices have been coming down. I should have sold last year.

  • April 12, 2013 to May 14, 2013: billed for 253 kWh; 539 kWh generated by solar (74%); total consumption = 729 kWh

  • For our 2013 Howard County property tax statement, $2801.68 was deducted from our payment for "Energy Device Credit" (solar panels). We still had to make a payment but this was for ad valorem charge, fire tax, state property tax, and trash fee. But our county tax for the year was zero.

  • May 14, 2013 to June 13, 2013: billed for 325 kWh; 475 kWh generated by solar (59%); total consumption = 800 kWh. As compared with last year, we used an average of 7.36 kWh more electricity per day. There are a couple reasons I can think of that might help explain this. We started using the geothermal heat pump in cooling mode this late spring and summer. It isn't supposed to use much electricity in the low setting but we had it set to the auto setting, which I then changed to low on July 15, 2013. Also, from May 30 to June 7, the Network Interface Module (NIM) on the heat pump was not working due to an electrical surge. So things ran in the inefficient mode until the NIM could be replaced.

  • June 13, 2013 to July 15, 2013: billed for 281 kWh; 467 kWh generated by solar (62%); total consumption = 748 kWh. Our summer has been very rainy.

  • On August 29, 2013, I received $252.96 from SolSystems for the sale of two SRECs.

  • My SunPower Gateway that I use to monitor the status of the photovoltaic panels on my garage has not been working reliably. Problems started in the summer of 2013 with connection occasionally being lost and the wireless indicator light being red instead of green. I would simply unplug the power source then plug it back in and that would work. As of October, it seems I've been having to do this at least once a day. The Gateway is in the same location it has been in since 2010. On October 3, 2013, Jeff T. of Solar Energy World came out to have a look. He thinks something might have changed in the neighborhood. Perhaps the county put in a new solar panels that transmits information that is creating problems for my signal. The solution is to move my gateway closer to the inverter. He'll have to think of the best way to do this and get back to me. Of course it doesn't affect my energy production. It just makes monitoring a little more inconvenient. For some time after he came out, the problem seemed resolved but then starting in late November, I lost connectivity at least once a day. On December 7, 2013, Jeff returned with a Netgear 85 Mbps wall-plugged ethernet adapter, model XET1001. He placed that and the gateway in the basement near a window. This allowed the signal sent to travel a much shorter distance to the gateway. The signal from the gateway was then transmitted from the ethernet adapter in the basement to another ethernet adapter in my office which then sent the signal via ethernet cable to my modem.

  • July 15, 2013 to August 15, 2013: billed for 15 kWh; 602 kWh generated by solar (98%); total consumption = 617 kWh. 87 kwh were generated by the panels on the house (which went operational on August 8) while 602 kwh were generated by the panels on the garage.

  • August 15, 2013 to November 13, 2013: billed for 0 kWh. My statement showed "accrued carryover kWh" of -500 meaning that at one point, we had 500 kWh surplus.

  • On the evening of December 11, 2013, our surplus of electricity as recorded by the new net meter installed on August 16 ran out. In other words, when it was first installed, the net meter read zero. Then it ran backwards because we generated more electricity than we consumed. At one point it said we had 500 kwh surplus. But as the days got shorter, we used up this surplus. As of December 11, we are back to zero.

  • In November 2013, I sold one SREC for $128.

  • November 13 to December 13, 2013: billed for 0 kWh. My statement showed "accrued carryover kWh" of -2 meaning that as of December 13, we were down to our last 2 kwh of surplus. In actuality, we were no longer in surplus mode since we used up all our surplus as of December 11. I guess energy company was a little behind.

  • On December 21, 2013, my SunPower Gateway lost connectivity again, despite Jeff T's Netgear installation. I did the usual reboot and it worked. It lost connectivity again around Christmas.

  • December 13, 2013 to January 15, 2014: billed for 580 kWh; 312 kWh generated by solar (35%); total consumption = 893 kWh. 129 kWh were generated by the panels on the house while 183 kWh were generated by the panels on the garage. It is a shame that it took so long to accummulate 500 kWh of surplus energy and only about 3.5 weeks to use that same amount.

  • Our winter has been the coldest I can ever remember. When we get snow, it tends to stick around meaning that my solar panels aren't earning their keep. If we had a steeper roof, the snow wouldn't stick around so long. The slope of our house roof that supports the Suniva panels is 27 degrees and the solar access is 89% (see third photo). For the garage, which supports the Sunpower panels, the slope is 17 degrees and the solar access is 98% (see fourth photo). There is a pretty obvious difference in how much snow remains when comparing the two. My neighbor across the street has a roof with a slope of 45 degrees and solar access of about 92% (see fifth photo). Their Mage panels have no snow when my Sunivas have about 40% snow coverage and my Sunpowers have about 95% snow coverage. Like my Sunpowers, my neighbor's roof faces south (an azimuth of 170 degrees).

    Just what is the ideal slope for solar panels? That all depends on where you live. According to Optimum Tilt of Solar Panels,
    If your solar panels will have a fixed tilt angle, and you want to get the most energy over the whole year, then this section is for you. A fixed angle is convenient, but note that there are some disadvantages. As mentioned above, you’ll get less power than if you adjusted the angle. Also, if you live where there is snow, adjusting the panels to a steeper angle in winter makes it more likely that they will shed snow. A panel covered in snow produces little or no power.
    Use one of these formulas to find the best angle from the horizontal at which the panel should be tilted:
         If your latitude is below 25°, use the latitude times 0.87.
         If your latitude is between 25° and 50°, use the latitude, times 0.76, plus 3.1 degrees.
         If your latitude is above 50°, see Other Situations below.
    [you have to see the original reference for that]
    Baltimore has a latitude of 39.2833 north. So the ideal slope for solar panels in the Baltimore area is (39.2833 x 0.76) + 3.1 = 32.9553 degrees.

    February 2014: My Sunpower wireless display (SPR-PMR-WDISP), part number 109874 quit working. I put in new batteries and it displayed a few meaningless numbers which faded away quickly while the light came on and wouldn't shut off. Normally, the light only turns on when the device is pressed. I informed Solar Energy World.

  • January 15, 2014 to February 13, 2014: billed for 543 kWh; 324 kWh generated by solar (37%); total consumption = 867 kWh. 132 kWh were generated by the panels on the house while 192 kWh were generated by the panels on the garage.

  • Our cost for electricity during this period is $0.0859 per kWh from Washington Gas Energy Services. Naturally, this is a variable cost since it is based on the number of kWh we consume. There are also taxes or fees that are variable. These total $0.03634 per kWh bringing the total variable cost to $0.12224 per kWh. There is also a fixed fee of $7.86 that is not dependent on how much energy we use. Even if we use no energy, we still have to pay the fixed fee every month. So how much of our bill goes to pay for these "other" costs? For us, the taxes and fees comprise 30% of our variable costs and 37% of the total cost.

    In late January 2014, I switch my electric supplier from Castlebridge to Constellation. This was a two year contract that locked my electric rates in for 8.59 cents per kilowatt hour. This was much higher than our previous rate with Castlebridge which was 7.79 center per kilowatt hour but we also got a $50 gift card. Considering how little electricity we pay for, we clearly came out ahead on this one. My tenants got 8.49 cents per kilowatt hour and 58.9 cents per therm. So not as good of a rate for them but certainly better than what the competition was offering. This was a two year contract.

  • In March 2014, I received $137.95 from SolSystems for selling one SREC.

  • February 13, 2014 to March 13, 2014: billed for 430 kWh; 499 kWh generated by solar (54%); total consumption = 929 kWh. 292 kWh were generated by the panels on the house while 207 kWh were generated by the panels on the garage.

  • Sometime around spring equinox seems to be about when the net meter noticeably started running backwards over the course of 24 hours, assuming the sun was out.

  • March 13, 2014 to April 14, 2014: billed for 129 kWh; 676 kWh generated by solar (84%); total consumption = 805 kWh. 263 kWh were generated by the panels on the house while 413 kWh were generated by the panels on the garage.

  • April 14, 2014 to May 14, 2014: billed for 0 kWh; 827 kWh generated by solar (100%); 327 kWh were generated by the panels on the house while 500 kWh were generated by the panels on the garage.

  • On May 29, 2014, I received $254.76 for selling two SRECs.

  • For our 2014 Howard County property tax statement, $2198.32 was deducted from our payment for "Energy Device Credit" (solar panels).

  • May 14, 2014 to June 13, 2014: billed for 0 kWh; 852 kWh generated by solar (100%); 331 kWh were generated by the panels on the house while 521 kWh were generated by the panels on the garage.

  • June 13, 2014 to July 15, 2014: billed for 0 kWh; 808 kWh generated by solar (100%); 378 kWh were generated by the panels on the house while 430 kWh were generated by the panels on the garage. Normally, the panels on the house generate about 65% as much electricity as panels on the garage but the panels on the garage did not generate any electricity on June 16-22, 24, and 25. Over these days, it should have produced about 151 kwh, worth $18.40. On July 19, 2014, I mentioned this to Brent. He got back to me quickly and said Danny P. would be in touch. See the Sunpower generation from June 13 to July 15 in the sixth image. Compare this to the Suniva generation over the same dates in the seventh image. No electricity was generated on July 2 either.

  • I compared what the website reports to that which the SunPower Wireless Display SPR-PMR-WDISP reports. The discrepancy was significant. But Geoff M. told me that the wireless display is not accurate and has been discontinued due to its unreliability.

    Danny P. mentioned the following:
    Typically when the monitoring drops out, your system is still producing power [but] you just can't see it on the website. You can verify this by looking at the SunPower inverter mounted on your garage. If you have a solid green light during the day you are not losing any production. Keep in mind the inverters are not considered revenue grade meters. The data they are displaying is +/- 5%. The solar meter we installed is the only device that is considered to be revenue grade which is +/- 2%. The meter is the most accurate measuring device in the entire system.

    On August 6, 2014, Jeff T. came by to check on my system. He found nothing wrong with it and he said that the SunPower inverters are known for being very reliable. He called SunPower who said they are going to start tracking my system. They were confused that the data logger had lost the data from June 16-22, 24, 25, and July 2. It has not had any problems since then. If I have more blank spots, I should give SunPower a call at 1-800-786-7693 and they should be able to help. Unfortunately, I generally don't find out about these problems until long after it has happened since I don't monitor the website daily. I wonder if it might have something to do with solar flares. I've been reading that we are at a 12 year peak. But if that were the case, I expect a lot more than just my system would be affected.

    On August 16, 2014, our net meter read 880 kwh at the end of the day. This is exactly one year after it was installed. If I was electrically net zero, then it would have read zero or negative. Clearly I am far from this and have lots of room to improve. I blame the excessively cold winter, the fact that the geothermal heat pump was not working properly for much of the winter, and the energy used by the chickens' heat lamp (220 watts for 24 hours a day, 7 days a week, for about 5 weeks = ~185 kwh). Also, we still use some incandescent bulbs that we're waiting to have burn out so we can replace with energy-efficient LED. Yes, those are my excuses and I'm sticking to them. But the truth of the matter is that even without those obstacles, I really don't know if we would have been net zero. I guess I'll have to wait until next year to see how we're doing.

    On August 27, 2014, Norma and I returned from our vacation. I checked the output from the solar panels and once again, I find that the SunPower panels are failing to show energy generation on days that they should. It started on August 12 where the dashboard only showed 0.74 kwh generation. Then on August 13-16, it showed no generation. See eighth image. In contrast, the Suniva panels generated 51.32 kwh over the same period. See ninth image. This means the SunPower panels should have produced about 78 kwh. The next day, I called Abby at SunPower, 1-800-786-7693. She had a note from Jeff Thomas of Solar Energy World describing my problem and SunPower had started tracking my system on August 6. She consulted with an engineer and assured me that the problem is with monitoring and not with the system producing electricity. She said that the system could have been reset and I should call again if I have the same problem. They will note it in their records. I explained that SolSystems uses this SunPower website to determine how many SRECs I've earned. She was not familiar with SolSystems so I told her it is an SREC brokerage firm. They need to accurately measure how much electricity my solar panels generate in order to ensure I get the SRECs I deserve. If the SunPower site does not reflect this, then I am not getting my fair share of SRECs. On September 1, 2014, I sent her this information along with a link to the SolSystems website by sending an email to customersupport@sunpower.com and including "Attn: Abby" in the subject. She did NOT get back to me. Very disappointing.

  • On August 29, 2014, I received $239.68 for selling two SRECs.

  • July 15, 2014 to August 14, 2014: billed for 0 kWh; 794 kWh generated by solar (100%); 322 kWh were generated by the panels on the house while 472 kWh were generated by the panels on the garage. Normally, the panels on the house generate about 65% as much electricity as panels on the garage but the panels on the garage did not report any electricity on August 13-14 while only a minimal amount of electric generation was reported for August 12. Over these days, it should have reported about 38 kwh. This is 38 kwh that could have been used for SREC reporting. Estimated total electric consumption was about 617 kwh based on 2013 estimates.

  • On September 25 and 26, 2014, I found that my SunPower dashboard failed to record the day's energy production. There was sun, yet it recorded zero electricity generation. See tenth image. In contrast, my Suniva panels generated 3.92 and 3.01 kWh on the 25th and 26th, respectively. This means my SunPower panels should have produced about 6.125 and 4.703 kWh on these days, respectively. Note that in this image, the dashboard reports that the problem started on September 24 with the message
    We have detected a communication problem with your system. Click here for help.
    I clicked it and got the message
    TROUBLESHOOTING: LOST CONNECTION
    Lease system customers, please call: 1-800-SUNPOWER.
    Non-leased system owners, please contact your Dealer.
    Dealer Name : Solar Energy World
    I checked my SunPower inverter which records the number of kWh generated by these panels and it did indeed verify that even though the dashboard did not report energy generation, power was being generated.

    On September 27, 2014, I found that my SunPower Gateway was not functioning properly. Rather than showing a green light for next to "Wireless" on the gateway, it showed a red light. I unplugged it then plugged it back in to make it green again. Shortly after, the SunPower dashboard began working. See eleventh image. What is strange is that it showed almost 20 kWh electricity generation between 1600 and 1700. This is not correct. This bar in the histogram actually represents the electricity generation for the day up to that time. While I am not pleased with the gateway, the dashboard, or (more importantly) SunPower customer support, I can say that I think now know how to fix the system if the dashboard fails to report energy generation.

    I think we reached our netmeter low point for the year. It showed 628 kwh on October 10, 2014. This is just a few days after the fall equinox.

  • August 14, 2014 to September 15, 2014: billed for 0 kWh; 742 kWh generated by solar (100%); 307 kWh were generated by the panels on the house while 435 kWh were generated by the panels on the garage. Normally, the panels on the house generate about 65% as much electricity as panels on the garage but the panels on the garage did not report any electricity on August 14-17. Over these days, it should have reported about 71 kwh. This is 71 kwh that could have been used for SREC reporting. Estimated total electric consumption was about 660 kwh based on 2012 estimates (2013 estimate for this time period not available).

  • September 15, 2014 to October 15, 2014: billed for 0 kWh; 566 kWh generated by solar (100%); 222 kWh were generated by the panels on the house while 344 kWh were generated by the panels on the garage. Normally, the panels on the house generate about 65% as much electricity as panels on the garage but the panels on the garage did not report any electricity on September 25-26. Over these days, it should have reported about 21 kwh. This is 21 kwh that could have been used for SREC reporting. Estimated total electric consumption was about 642 kwh based on 2012 estimates (2013 estimate for this time period not available).

  • On October 28, 2014, my SunPower system reported only 0.87 kwh for the day. In contrast, the Suniva panels reported 8.7 kwh. This means the SunPower panels should have reported about 13.38 kwh. The SunPower website gave me the usual error message:
    TROUBLESHOOTING: LOST CONNECTION
    Lease system customers, please call 1-800-SUNPOWER.
    Non-leased system owners, please contact your Dealer.
    Dealer Name: Solar Energy World


    On November 9, 2014, my SunPower panels stopped registering energy generation sometime after 1000 for the rest of the day. I know there was plenty of sun because my Suniva panels were generating plenty of electricity (6.55 kwh) and the SunPower website reported only 5 kwh for the day and displayed an error message.

    On November 18, 2014, my SunPower wireless display SPR-PMR-WSIDP part number 109874 quit working again. I did a reset by inserting the end of a paperclip into the small hole in the back. This caused an icon at the bottom of the screen to cycle between looking like a two link chain to a broken chain. I had never seen this before. I also tried removing and replacing the batteries. Still no go. It is getting power but it isn't displaying any useful information. Fortunately, this device is not needed to send data to the SunPower website although I have used it to let me know if there is an issue with communication without having to log in.

  • October 15, 2014 to November 13, 2014: billed for 0 kWh; 466 kWh generated by solar (69%); 186 kWh were generated by the panels on the house while 280 kWh were generated by the panels on the garage. Normally, the panels on the house generate about 65% as much electricity as panels on the garage but the panels on the garage did not report any electricity on most of November 9, all of October 27, and most of October 28. Over these days, it should have reported about 32 kwh extra. This is 32 kwh that could have been used for SREC reporting. Total electric consumption was 674 kWh.

  • On November 19, 2014, I noticed that my SolSystems account has never shown SRECs generated for my Suniva panels. These panels are reflected as a 2.65 kW system and to date it has generated 3,729.77 kWh. So it should have earned 3 SRECs, not zero. I reported this to SolSystems. The 3.68 kW system is for my SunPower system and that I have received several SRECs for that. Then thee is also my solar thermal hot water system which generates SRECs on a predictable basis. Because there is no monitoring, the SRECs are simply allocated so that I receive 2.256 per year from this system.

    On November 21, 2014, I received an e-mail from Victoria at SolSystems informing me that they made a change to my account so that my two photovoltaic systems are now reflected as one 6.33 kW system. She also asked me to provide my current meter production. I replied with information posted by the provider websites, the inverters, and the Suniva meter. My SunPower system does not have its own production meter. Here is the important information, accurate as of November 23, 2014 at 1415:
  • Suniva Inverter: 3850 kwh
  • SunPower Inverter: 19,268 kWh

  • I asked Victoria if the two photovoltaic systems could be kept separate so I could track the performance of each. She said
    It is currently not possible to keep the two systems separate because they are treated as one system by the state and regulatory bodies. Going forward, we will not be able to access your readings remotely because your have two separate remote monitoring systems. But rather, you will need to log into your system pages and enter your total system readings (including your expansion) on a monthly basis. We will send you a reminder email on the 27th and 5th of each month to enter your readings. Please let us know if you have any additional questions.

    On December 7, 2014, I reported the following to SolSystems.
  • Suniva Inverter: 3890 kWh
  • SunPower Inverter: 19,336 kWh
  • Total: 23,226 kWh

  • I think the issue with my inverter not communicating with the SunPower website might be resolved. When Jeff was here awhile back, he asked if there was any wireless device that might be interfering with the signal from the inverter. I said no. Later, I had problems with the fan between my office (on the main floor) and the downstairs bedroom. The thermostat for this operates wirelessly. I hadn't thought about this when Jeff and I spoke. The thermostat was losing connectivity to the fan so I moved it closer. Problem solved. But it also appears that the inverter is now communicating more reliably with the SunPower website.

  • November 13, 2014 to December 12, 2014: billed for 0 kWh; 335 kWh generated by solar (38%); 120 kWh were generated by the panels on the house while 215 kWh were generated by the panels on the garage. Total electric consumption was 887 kWh.

  • I've never been much into decorating my home with Christmas lights but Norma enjoys it. We have our pine tree and front roof gutters decorated with at least some LED and possibly some non-LED lights. I would describe it as a modest display. These are controled by an outdoor timer/splitter. I measured electric consumption over 6 days from Christmas to New Years Eve. It averaged 1.28 kWh per day, roughly equivalent to 15.6 cents per day.

    On January 16, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 3993 kWh
  • SunPower Inverter: 19,501 kWh
  • Total: 23,494 kWh

  • December 12, 2014 to January 14, 2014: billed for 569 kWh; 334 kWh generated by solar (37%); 120 kWh were generated by the panels on the house while 214 kWh were generated by the panels on the garage. Total electric consumption was 903 kWh.

  • On February 16, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 4134 kWh
  • SunPower Inverter: 19,725 kWh
  • Total: 23,859 kWh

  • January 14, 2015 to February 13, 2015: billed for 611 kWh; 400 kWh generated by solar (65%); 151 kWh were generated by the panels on the house while 249 kWh were generated by the panels on the garage. Total electric consumption was 1011 kWh.

  • On March 2, 2015, I received $308.44 from SolSystems for the sale of two SRECs.

  • February 13, 2015 to March 13, 2015: billed for 778 kWh; 278 kWh generated by solar (26%); 151 kWh were generated by the panels on the house while 127 kWh were generated by the panels on the garage. This is due to a large amount snow and the fact that the garage roof is not as steep as the house roof. Total electric consumption was 1056 kWh.

  • On March 21, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 4333 kWh
  • SunPower Inverter: 19,916 kWh
  • Total: 24,249 kWh

  • March 13, 2015 to April 14, 2015: billed for 70 kWh; 757 kWh generated by solar (92%); 296 kWh were generated by the panels on the house while 461 kWh were generated by the panels on the garage. Total electric consumption was 827 kWh.

  • On April 21, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 4632 kWh
  • SunPower Inverter: 20,383 kWh
  • Total: 25,015 kWh

  • On May 13, 2015, I reported the following to SolSystems. Their website seemed to think I generated too much electricity so it requested I submit a photo. Since I have two systems, I had to paste both images into one.
  • Suniva Inverter: 4880 kWh
  • SunPower Inverter: 20,785 kWh
  • Total: 25,665 kWh

  • April 14, 2015 to May 13, 2015: billed for 0 kWh; 845 kWh generated by solar (100%); 319 kWh were generated by the panels on the house while 526 kWh were generated by the panels on the garage. Total electric consumption was 577 kWh.

  • On May 29, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 5065 kWh
  • SunPower Inverter: 21,073 kWh
  • Total: 26,138 kWh

  • May 13, 2015 to June 15, 2015: billed for 0 kWh; 946 kWh generated by solar (100%); 367 kWh were generated by the panels on the house while 579 kWh were generated by the panels on the garage. Total electric consumption was 715 kWh.

  • On June 24, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 5332 kWh
  • SunPower Inverter: 21,484 kWh
  • Total: 26,816 kWh

  • June 15, 2015 to July 15, 2015: billed for 0 kWh; 787 kWh generated by solar (100%); 306 kWh were generated by the panels on the house while 481 kWh were generated by the panels on the garage. Total electric consumption was 767 kWh.

  • On July 22, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 5624 kWh
  • SunPower Inverter: 21,934 kWh
  • Total: 27,558 kWh

  • July 15, 2015 to August 14, 2015: billed for 0 kWh; 858 kWh generated by solar (100%); 531 kWh were generated by the panels on the house while 327 kWh were generated by the panels on the garage. Total electric consumption was 758 kWh.

  • On August 29, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 6014 kWh
  • SunPower Inverter: 22,576 kWh
  • Total: 28,590 kWh

  • On September 4, 2015, I received $497.07 from SolSystems for the sale of three SRECs at $165.69 each.

  • August 14, 2015 to September 15, 2015: billed for 0 kWh; Approximately 887 kWh generated by solar (100%); about 558 kWh were generated by the panels on the garage while 329 kWh were generated by the panels on the house. Total electric consumption was 803 kWh. The reason energy produced by the Sunpower panels is an approximation is because there were issues with the Sunpower website. I informed them of the problem on September 20, 2015. It is possible the problem was with the transmitter because no report was produced for August 14 to September 8. But when I went back a month prior and tried to review data that I know existed a month ago, all I got was a message that said "Waiting for Data." An hour later, it said the same thing. See twelfth image. Thus, my approximation is based on the proportion of energy the Sunpower panels produced relative to the Suniva panels for the latest reading.

  • On September 20, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 6233 kWh
  • SunPower Inverter: 22,948 kWh
  • Total: 29,181 kWh

  • On September 25, 2015, Christine P. of Sunpower sent me an e-mail to inform me that the problem with their website, which I reported on September 20, was fixed. It turns out my panels on the garage actually generated 567 kWh of electricity from August 14, 2015 to September 15, 2015. My earlier estimate was 558 kWh so I was off by 9 kWh 1.6%. Not bad.

  • September 15, 2015 to October 14, 2015: billed for 0 kWh; Approximately 585 kWh generated by solar (98%); about 368 kWh were generated by the panels on the garage while 217 kWh were generated by the panels on the house. Total electric consumption was 596 kWh. The reason energy produced by the Sunpower panels is an approximation is because there were issues with the Sunpower website. I informed them of the problem around October 24, 2015. Christine P. replied back to me with the following:
    The data logger device doesn't have the capability to save the data if it has been reset or if it was down and therefore cannot be retrieved.
    I was not pleased her answer.

  • On November 3, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 6528 kWh
  • SunPower Inverter: 23,447 kWh
  • Total: 29,975 kWh

  • October 14, 2015 to November 12, 2015: billed for 0 kWh; Approximately 490 kWh generated by solar (72%); about 310 kWh were generated by the panels on the garage while 180 kWh were generated by the panels on the house. Total electric consumption was 677 kWh. The reason energy produced by the Sunpower panels is an approximation is because there were issues with the Sunpower website.

  • On November 26, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 6653 kWh
  • SunPower Inverter: 23,664 kWh
  • Total: 30,317 kWh

  • On December 13, 2015, I received $316.78 from SolSystems for the sale of two SRECs at $158.39 each.

  • November 12, 2015 to December 12, 2015: billed for 0 kWh; 433 kWh generated by solar (59%); 278 kWh were generated by the panels on the garage while 155 kWh were generated by the panels on the house. Total electric consumption was 737 kWh.

  • On December 28, 2015, I reported the following to SolSystems.
  • Suniva Inverter: 6762 kWh
  • SunPower Inverter: 23,853 kWh
  • Total: 30,615 kWh

  • December 12, 2015 to January 14, 2016: billed for 558 kWh; 343 kWh generated by solar (38%); 217 kWh were generated by the panels on the garage while 126 kWh were generated by the panels on the house. Total electric consumption was 901 kWh.

  • On January 18, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 6856 kWh
  • SunPower Inverter: 24,022 kWh
  • Total: 30,878 kWh

  • On February 15, 2015, Presidents Day, I contacted Constellation. My contract had ended and if I did not find a new energy provider, my rates would go from 8.59 cents per kilowatt hour in Savage to 10.29 cents per kilowatt hour. At my rental house in Hanover, my rate would go from 8.49 center per kilowatt hour to 10.29 cents per kilowatt hour and from 58.9 cents per therm to 49.9 cents per therm. Yes, the natural gas cost would go down! I checked out the costs of other providers at BGE Energy Suppliers and Choose Energy. The latter will find you an inexpensive energy provider quickly but may not provide the absolute cheapest since "cheap" is subjective depending on things like fixed rate, variable rate, length of contract, fees, etc. Still, I would recommend it if you don't want to put a lot of time looking for providers.

    I decided to go with Clearview for electricity for both my house and the Hanover house. I also switched to Shipley Energy for natural gas for the Hanover house. I could not find any good offers that included gift cards. Maybe they found that they were losing money with folks like me that own solar panels.

    The Clearview electric rate is 8.49 cents per kilowatt hour with no base rate. This is a 12 month contract with a fixed rate for both my house and the Hanover house. They have a 8.29 cents per kilowatt hour rate that also has $9.99 per month base rate. I didn't think the latter was cost worthy.

    The Shipley natural gas rate is 36.9 cents per therm. This is a variable rate plan so it can go up or down. There is also a one dollar per month fee. This is not under contract and there is no cancellation fee. I typically don't like a variable rate but the cost of natural gas has been pretty low and might continue to drop. In their January 6 to February 3, 2016 gas bill, my tenants used 176 therms, paying $103.66 for gas at 58.9 cents per therm. If they were paying at 36.9 cents per therm, their cost would have been $64.94, a savings of $38.72 (37% less)! I was asked to let Constellation know when I switched providers.

    On February 15, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 6994 kWh
  • SunPower Inverter: 24,203 kWh
  • Total: 31,197 kWh

  • January 14, 2016 to February 12, 2016: billed for 621 kWh; 325 kWh generated by solar (34%); 188 kWh were generated by the panels on the garage while 137 kWh were generated by the panels on the house. Total electric consumption was 946 kWh.

  • On March 10, 2016, I received $372.66 from SolSystems for the sale of three SRECs at $124.22 each.

  • February 12, 2016 to March 14, 2016: billed for 237 kWh; 569 kWh generated by solar (71%); 353 kWh were generated by the panels on the garage while 216 kWh were generated by the panels on the house. Total electric consumption was 806 kWh.

  • On March 27, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 7301 kWh
  • SunPower Inverter: 24,694 kWh
  • Total: 31,995 kWh

  • March 14, 2016 to April 14, 2016: billed for 0 kWh; 815 kWh generated by solar (100%); 502 kWh were generated by the panels on the garage while 313 kWh were generated by the panels on the house. Total electric consumption was 713 kWh.

  • On April 20, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 7583 kWh
  • SunPower Inverter: 25,142 kWh
  • Total: 32,725 kWh

  • April 14, 2016 to May 13, 2016: billed for 0 kWh; 630 kWh generated by solar (100%, we had many cloudy days); 388 kWh were generated by the panels on the garage while 242 kWh were generated by the panels on the house. Total electric consumption was 529 kWh (we were on vacation for about 10 days).

  • On May 17, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 7772 kWh
  • SunPower Inverter: 25,430 kWh
  • Total: 32,202 kWh

  • On May 31, 2016, I received $67.78 for selling two SRECs to SolSystems at $33.89 each. The value dropped significantly.

  • May 13, 2016 to June 15, 2016: billed for 0 kWh; 912 kWh generated by solar (100%); 554 kWh were generated by the panels on the garage while 358 kWh were generated by the panels on the house. Total electric consumption was 696 kWh.

  • On June 27, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 8216 kWh
  • SunPower Inverter: 26,104 kWh
  • Total: 34,320 kWh

  • On July 15, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 8415 kWh
  • SunPower Inverter: 26,415 kWh
  • Total: 34,830 kWh

  • June 15, 2016 to July 14, 2016: billed for 0 kWh; 826 kWh generated by solar (100%); 505 kWh were generated by the panels on the garage while 321 kWh were generated by the panels on the house. Total electric consumption was 627 kWh.

  • On August 8, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 8668 kWh
  • SunPower Inverter: 26,820 kWh
  • Total: 35,488 kWh

  • July 14, 2016 to August 15, 2016: billed for 0 kWh; 896 kWh generated by solar (100%); 558 kWh were generated by the panels on the garage while 338 kWh were generated by the panels on the house. Total electric consumption was 796 kWh.

  • On September 2, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 8913 kWh
  • SunPower Inverter: 27,245 kWh
  • Total: 36,158 kWh

  • August 15, 2016 to September 15, 2016: billed for 0 kWh; 875 kWh generated by solar (100%); 555 kWh were generated by the panels on the garage while 320 kWh were generated by the panels on the house. Total electric consumption was 745 kWh.

  • On October 1, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 9141 kWh
  • SunPower Inverter: 27,620 kWh
  • Total: 36,761 kWh

  • September 15, 2016 to October 14, 2016: billed for 0 kWh; 527 kWh generated by solar (100%); 326 kWh were generated by the panels on the garage while 201 kWh were generated by the panels on the house. Total electric consumption was 533 kWh.

  • On October 22, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 9301 kWh
  • SunPower Inverter: 27,881 kWh
  • Total: 37,182 kWh

  • October 14, 2016 to November 14, 2016: billed for 0 kWh; 638 kWh generated by solar (100%); 405 kWh were generated by the panels on the garage while 233 kWh were generated by the panels on the house. Total electric consumption was 701 kWh.

  • On November 20, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 9500 kWh
  • SunPower Inverter: 28,221 kWh
  • Total: 37,721 kWh

  • On November 29, 2016, I received $44.34 for selling three SRECs to SolSystems at $14.78 each.

  • On December 17, 2016, I reported the following to SolSystems.
  • Suniva Inverter: 9630 kWh
  • SunPower Inverter: 28,441 kWh
  • Total: 38,071 kWh

  • November 14, 2016 to December 14, 2016: billed for 0 kWh; 419 kWh generated by solar; 266 kWh were generated by the panels on the garage while 153 kWh were generated by the panels on the house. Total electric consumption was 797 kWh.

  • On January 27, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 9781 kWh
  • SunPower Inverter: 28,693 kWh
  • Total: 38,474 kWh

  • December 14, 2016 to January 14, 2017: billed for 743 kWh; 334 kWh generated by solar; 212 kWh were generated by the panels on the garage while 122 kWh were generated by the panels on the house. Total electric consumption was 1077 kWh.

  • On March 5, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 10,028 kWh
  • SunPower Inverter: 29,094 kWh
  • Total: 39,122 kWh

  • January 14, 2017 to February 13, 2017: billed for 571 kWh; 362 kWh generated by solar; 225 kWh were generated by the panels on the garage while 137 kWh were generated by the panels on the house. Total electric consumption was 933 kWh.

  • On March 14, 2017, I switched energy providers at both my Savage and Hanover homes. To choose the best rates, I employed Choose Energy and BGE - My Supplier Options. I found the former wasn't always accurate but it was very useful in helping rank the numerous choices available.

    I called Clearview Energy, who had been providing electricity over the last several months at a rate of $0.0849/kWh. I asked them to cancel my service at both homes until the new provider took over. Next I called Shipley Energy, who had been providing gas at the townhouse over the last several months at a variable rate, with the latest being $0.5613/therm. I also asked them to cancel my service until the new provider took over.
    I then signed an 18 month fixed rate contract with Direct Energy. This contract is called "Live Brighter 18." I will purchase electricity at $0.0769/kWh. This means a savings of about 9.4%. This is for both houses. I also signed a 24 month fixed rate contract with Constellation. I will purchase gas at the townhouse for $0.519/therm. This means a savings of about 7.5% if compared to the last month's rate.

  • February 13, 2017 to March 14, 2017: billed for 33 kWh; 661 kWh generated by solar; 410 kWh were generated by the panels on the garage while 251 kWh were generated by the panels on the house. Total electric consumption was 694 kWh.

  • March 14, 2017 to April 13, 2017: billed for 67 kWh; 683 kWh generated by solar; 423 kWh were generated by the panels on the garage while 260 kWh were generated by the panels on the house. Total electric consumption was 750 kWh.

  • On April 23, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 10,462 kWh
  • SunPower Inverter: 29,786 kWh
  • Total: 40,248 kWh

  • April 13, 2017 to May 12, 2017: billed for 0 kWh; 645 kWh generated by solar; 394 kWh were generated by the panels on the garage while 251 kWh were generated by the panels on the house. Total electric consumption was 534 kWh. We've had a dark spring. I've had to turn on the electric heating element on our solar hot water heater twice now because there wasn't enough sun over several days. Never had to do this before so early in the year. Looking at the solar photovoltaic generation, the production hasn't been this low since the January 14, 2017 to February 13, 2017 period.

  • On May 27, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 10,753 kWh
  • SunPower Inverter: 30,235 kWh
  • Total: 40,988 kWh

  • May 12, 2017 to June 15, 2017: billed for 0 kWh; 863 kWh generated by solar; 525 kWh were generated by the panels on the garage while 338 kWh were generated by the panels on the house. Total electric consumption was 618 kWh.

  • On June 30, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 11,116 kWh
  • SunPower Inverter: 30,789 kWh
  • Total: 41,905 kWh

  • June 15, 2017 to July 14, 2017: billed for 0 kWh; 805 kWh generated by solar; 492 kWh were generated by the panels on the garage while 313 kWh were generated by the panels on the house. Total electric consumption was 707 kWh.

  • On July 21, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 11,333 kWh
  • SunPower Inverter: 31,132 kWh
  • Total: 42,465 kWh

  • July 14, 2017 to August 14, 2017: billed for 0 kWh; 771 kWh generated by solar; 482 kWh were generated by the panels on the garage while 291 kWh were generated by the panels on the house. Total electric consumption was 661 kWh.

  • On September 1, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 11,708 kWh
  • SunPower Inverter: 31,753 kWh
  • Total: 43,461 kWh


  • August 14, 2017 to September 15, 2017: billed for 0 kWh; 728 kWh generated by solar; 460 kWh were generated by the panels on the garage while 261 kWh were generated by the panels on the house. Total electric consumption was 603 kWh.

  • On October 1, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 11,951 kWh
  • SunPower Inverter: 32,170 kWh
  • Total: 44,121 kWh


  • September 15, 2017 to October 14, 2017: billed for 0 kWh; 592 kWh generated by solar; 376 kWh were generated by the panels on the garage while 216 kWh were generated by the panels on the house. Total electric consumption was 563 kWh.

  • On October 20, 2017, I reported the following to SolSystems.
  • Suniva Inverter: 12,068 kWh
  • SunPower Inverter: 32,364 kWh
  • Total: 44,432 kWh




  • First year solar energy generation summary

    December 8, 2010 to December 7, 2011: Actually, energy was generated on December 7 but for only half a day so I'm starting at the first full day of energy generation.

    Total energy generated by solar panels: 4776 kWh
    Average daily generation: 13.08 kWh
    Money saved through electricity savings based on Dominion 2011 electricity rate of $0.0919 per kWh: $438.91
    Considering delivery service, taxes, and surcharges that are a function of the amount of electricity purchased, the actual total rate is $0.1163454 per kWh, which equates to an annual savings of $555.66
    Total amount of electricity purchased from December 13, 2010 to December 12, 2011: 2795 kWh; this equates to $256.86 for the electricity alone or $325.18 after delivery service, taxes, and surcharges that are a function of the amount of electricity purchased
    Total amount of electricity consumed: 4776 + 2795 = 7571 kWh
    Solar panels provided 100 * (4776/7571) = 63% of our electricity

    How does this compare to what Solar Energy World predicted?
    They expected the panels would provide 48% of our electricity so we're actually doing significantly better. They also claimed we'd save $568 per year based on our 2009/2010 energy consumption. They were off by only 2%! Overall, we are quite pleased with the results.

    I did not sell any SRECs in 2011 but had I sold the 4 I generated (one for each megawatt hour) at the November 2011 clearing priced of $210, I would have made $840.

    The amount of electricity generated by my solar panels in one year had a signficant effect on the environment by offsetting the amount produced by conventional means. How can one compare generating 4776 kWh of solar energy?
  • My carbon footprint was reduced by an amount equivalent to 7926 pounds of carbon dioxide.
  • Emissions were reduced by an amount equivalent to planting 88 seedlings that were then grown for 10 years.
  • Emissions were reduced by an amount equivalent to not driving 7849 miles in a standard car.
  • - based on SunPower website



    First year energy summary...room for improvement

    Notice that I refer to the amount of electricity purchased and consumed instead of our electric bill. This is because I am not including things like the delivery service, taxes, or surcharges. Based on our last three electric bills for 2011, these fees average out to about $15.01 per month or $180.08 per year. But looking back on May 25, 2012, this was a mistake as I now see that at least some of these bills were a function of the amount of energy used, which is actually about $0.032572 per kilowatt hour. Hence, our electric only rate of $0.0899 is really an electric total rate of $0.122472, a difference of 26.6%. So I went back and added amounts so that both the "electric alone" amounts would be listed along with the total amounts based on both electricity, delivery service, taxes, and surcharges that are a function of the amount of electricity purchased. Fixed fees that are not dependent on the amount of electricity purchased were not included in this secondary amount. For our April 13, 2012 to May 15, 2012 bill, these fixed fees were $7.87, or 38% of the total bill.

    Taking this into consideration, had we not had solar panels, the cost of electricity purchased for the year would have been $438.91 + $256.86 = $695.77 while our electric bill would have been $695.77 + $180.08 = $875.85. With solar panels, our electric bill for the year is around $256.86 + $180.08 = $436.94.

    If you add to this our annual heating cost of $867.10 (based on oil heat cutting and monitoring costs), then our annual energy cost is $867.10 + $436.94 = $1304.04. Without solar panels, it would be $867.10 + $875.85 = $1742.95.

    According to a BGE Home folder I received, the annual energy bill for an average home is about $2200. So even without the help of solar energy, our energy costs are about 79% of average. But is it really?

    According to the National Association of Home Builders, the average home size in the United States was 2,700 square feet in 2009, up from 1,400 square feet in 1970.
    - from U.S. Home Size - Infoplease.com

    Our house has a finished square footage of 1240. This means it is 1240/2700 = 46% the size of the average American home. Obviously, our pre-solar energy costs are not 46% the amount that the average American pays...it is more like 1742.95/2200 = 79%! With the help of solar, our energy costs are only 1304.04/2200 = 59% of what the average American pays.

    So where are we weak? In the BGE Home folder, non-heating costs account for 71% while heatng costs account for 29%. Pre-solar, our non-heating costs account for 875.85/1742.95 = 50% while our heating costs account for 867.10/1742.95 = 50%. With the help of solar, our non-heating costs account for 436.94/1304.04 = 34% while our heating costs account for 867.10/1304.04 = 66%. Clearly, we are paying too much to heat our house. But in reality, these numbers don't tell the whole truth since heating and water heating are broken down into two different categories with water heating accounting for 14% of the average energy cost for a home. Our water heater is electric but it is supported by the oil heater in the winter. How much of it is supported by oil is something I do not know. But what I do know is that our heating costs are more than what they should be.

    Clearly there is room for improvement. On November 15, 2012, this improvement took place with the installation of a geothermal heat pump.



    Total solar savings

    So how much has it saved me?
  • $7345.50 federal tax refund for Sunpower solar panels. $3042 federal tax refund for Suniva solar panels. Total: $10,387.50 total federal tax refund.
  • $22.24 for December 13, 2010 to January 14, 2011 electric charges alone or $28.16 for total bill
  • $26.29 for January 14, 2011 to February 14, 2011 electric charges alone or $33.28 for total bill
  • $37.13 for February 14, 2011 to March 14, 2011 electric charges alone or $47.01 for total bill
  • $41.54 for March 14, 2011 to April 14, 2011 electric charges alone or $52.59 for total bill
  • $42.02 for April 14, 2011 to May 14, 2011 electric charges alone or $53.20 for total bill
  • $55.05 for May 14, 2011 to June 16, 2011 electric charges alone or $69.69 for total bill
  • $1840 Maryland state grant for solar panels
  • $51.46 for June 16, 2011 to July 16, 2011 electric charges alone or $65.15 for total bill
  • $46.59 for July 16, 2011 to August 12, 2011 electric charges alone or $58.98 for total bill
  • $42.37 for August 12, 2011 to September 15, 2011 electric charges alone or $53.64 for total bill
  • $40.25 for September 15, 2011 to October 15, 2011 electric charges alone or $50.96 for total bill
  • $30.79 for October 15, 2011 to November 12, 2011 electric charges alone or $38.98 for total bill
  • $23.71 for November 12, 2011 to December 12, 2011 electric charges alone or $30.02 for total bill
  • $22.49 for December 12, 2011 to January 14, 2012 electric charges alone or $28.47 for total bill
  • $70.84 for January 14, 2012 to March 14, 2012 electric charges alone or $89.68 for total bill
  • $41.89 for March 14 to April 13, 2012 electric charges alone or $53.03 for total bill
  • $45.22 for April 13, 2012 to May 15, 2012 electric charges alone or $61.60 for total bill
  • $49.48 for May 15, 2012 to June 14, 2012 electric charges alone or $67.54 for total bill
  • $48.25 for June 14, 2012 to July 14, 2012 electric charges alone or $67.30 for total bill
  • $47.10 for July 14, 2012 to August 16, 2012 electric charges alone or $65.69 for total bill
  • $42.84 for August 16, 2012 to September 15, 2012 electric charges alone or $59.76 for total bill
  • $36.28 for September 15, 2012 to October 15, 2012 electric charges alone or $50.61 for total bill
  • $26.35 for October 15, 2012 to November 13, 2012 electric charges alone or $35.89 for total bill
  • $20.49 for November 13 to December 12, 2012 electric charges alone or $28.54 for total bill
  • $18.54 for December 12, 2012 to January 14, 2013 electric charges alone or $25.42 for total bill
  • $19.09 for January 14, 2013 to February 13, 2013 electric charges alone or $27.37 for total bill
  • $28.20 for February 13, 2013 to March 14, 2013 electric charges alone or $41.85 for total bill
  • $35.52 for March 14, 2013 to April 12, 2013 electric charges alone or $53.16 for total bill
  • $1097.54 for selling 10 SRECs on May 28, 2013 via SolSystems
  • $41.99 for April 12, 2013 to May 14, 2013 electric charges alone or $60.69 for total bill
  • July 2013: $2801.68 for Howard County property tax credit.
  • $37 for May 14, 2013 to June 13, 2013 electric charges alone or $53.17 for total bill
  • $36.38 for June 13, 2013 to July 15, 2013 electric charges alone or $52.69 for total bill
  • $46.08 for July 15, 2013 to August 15, 2013 electric charges alone or $68.84 for total bill. Around this time, I started generating 2.256 SRECs per year for my solar hot water heater. These are added to my photovoltaic SREC generation. So it makes things a little more difficult to tell how things are paying for themselves.
  • $252.96 for selling 2 SRECs on August 29, 2013 via SolSystems
  • Above I mentioned that for the August 15 to November 13, 2013 period, we were billed for 0 kWh and in fact had a surplus. But this didn't mean our bill was zero. It just meant our only charges were three months of fees to include $7.50 per month for the "BGE Electric Delivery Service" and $0.37 per month for the "State/Local Taxes and Surcharges." This came to $23.61 or $7.87 per month. To estimate our savings, I looked at our energy usage for the same period in the previous year. This came to 660 + 642 + 572 = 1874 kWh. Using the rates from my August 15, 2013 statement, I assume our rate is $0.0779 per kWh for electricity alone or $0.11158 per kWh for total costs to include fees and taxes. This means that for this period, the solar panels saved us $145.98 in electric costs alone or $209.10 - $23.61 = $185.49 in total costs.
  • $128 for selling one SREC on November 25, 2013 via SolSystems
  • Above I mentioned that for the November 13 to December 13, 2013 period, we were billed for 0 kWh. Our only charges was for one month of fees to include $7.50 per month for the "BGE Electric Delivery Service" and $0.37 per month for the "State/Local Taxes and Surcharges." This came to $7.87. To estimate our savings, I looked at our energy usage for the same period in the previous year. This came to 741 kWh. Using the rates from my August 15, 2013 statement, I assume our rate is $0.0779 per kWh for electricity alone or $0.11158 per kWh for total costs to include fees and taxes. This means that for this period, the solar panels saved us $57.72 in electric costs alone or $82.68 - $7.87 = $74.81 in total costs.
  • $26.80 for December 13, 2013 to January 15, 2014 electric charges alone or $38.17 for total bill
  • $27.83 for January 15, 2014 to February 13, 2014 electric charges alone or $39.61 for total bill
  • $137.95 for selling one SREC in March 2014 via SolSystems
  • $42.86 for February 13, 2014 to March 13, 2014 electric charges alone or $60.83 for total bill
  • $58.07 for March 13, 2014 to April 14, 2014 electric charges alone or $82.39 for total bill
  • In our utility bill starting April 14, 2014, we paid only $7.50 per month for the "BGE Electric Delivery Service" and $0.36 per month for the "State/Local Taxes and Surcharges." To estimate our savings, I looked at our energy usage for the same period in the previous year(s).
  • Mid-April to mid-May 2014 estimated total consumption = 729 kWh; total savings estimate = (729 x $0.0859) - $7.86 = $54.76 in electric charges alone or (729 x $0.12188) - $7.86 = $80.99 for total bill
  • Mid-May to mid-June 2014 estimated total consumption = 800 kWh; total savings estimate = (800 x $0.0859) - $7.86 = $60.86 in electric charges alone or (800 x $0.12188) - $7.86 = $89.64 for total bill
  • July 2014: $2198.32 for Howard County property tax credit.
  • Mid-June to mid-July 2014 estimated total consumption = 748 kWh; total savings estimate = (748 x $0.0859) - $7.86 = $56.39 in electric charges alone or (748 x $0.12188) - $7.86 = $83.31 for total bill
  • $239.68 for selling two SRECs in August 2014 via SolSystems
  • $46.89 for July 15, 2014 to August 14, 2014 electric charges alone or $69.09 for total bill
  • $48.83 for August 14, 2014 to September 15, 2014 electric charges alone or $72.58 for total bill
  • $47.29 for September 15, 2014 to October 15, 2014 electric charges alone or $70.39 for total bill
  • $50.04 for October 15, 2014 to November 13, 2014 electric charges alone or $74.29 for total bill
  • $68.33 for November 13, 2014 to December 12, 2014 electric charges alone or $100.25 for total bill
  • $28.69 for December 12, 2014 to January 14, 2015 electric charges alone or $43.92 for total bill. Surplus credit electricity ran out in December.
  • $34.36 for January 14, 2015 to February 13, 2015 electric charges alone or $52.80 for total bill.
  • $308.44 for selling two SRECs on March 2, 2015 via SolSystems.
  • $23.88 for February 13, 2015 to March 13, 2015 electric charges alone or $35.15 for total bill.
  • $65.03 for March 13, 2015 to April 14, 2015 electric charges alone or $94.70 for total bill.
  • $64.73 for April 14, 2015 to May 13, 2015 electric charges alone or $97.85 for total bill.
  • $73.40 for May 13, 2015 to June 15, 2015 electric charges alone or $110.48 for total bill.
  • $150.44 for selling one SREC on June 1, 2015 via SolSystems.
  • $59.74 for June 15, 2015 to July 15, 2015 electric charges alone or $90.58 for total bill.
  • $68.72 for July 15, 2015 to August 14, 2015 electric charges alone or $102.36 for total bill.
  • $497.07 for selling three SRECs on September 4, 2015 via SolSystems.
  • $73.96 for August 14, 2015 to September 15, 2015 electric charges alone or $108.73 for total bill.
  • $42.39 for September 15, 2015 to October 14, 2015 electric charges alone or $65.32 for total bill.
  • $34.23 for October 14, 2015 to November 12, 2015 electric charges alone or $53.44 for total bill.
  • $316.78 for selling two SRECs on December 3, 2015 via SolSystems.
  • $29.33 for November 12, 2015 to December 12, 2015 electric charges alone or $46.41 for total bill.
  • $21.60 for December 12, 2015 to January 14, 2016 electric charges alone or $37.47 for total bill.
  • $20.06 for January 14, 2016 to February 12, 2016 electric charges alone or $35.09 for total bill.
  • $372.66 for selling three SRECs on March 10, 2016 via SolSystems.
  • $41.02 for February 12, 2016 to March 14, 2016 electric charges alone or $67.40 for total bill.
  • $61.33 for March 14, 2016 to April 14, 2016 electric charges alone or $99.13 for total bill.
  • $8.74 for once a year refund for excess power generation paid by BGE.
  • $45.63 for April 14, 2016 to May 13, 2016 electric charges alone or $74.84 for total bill.
  • $67.78 for selling two SRECs on May 31, 2016 via SolSystems. $33.89 each. Not sure why the price dropped so much.
  • $69.43 for May 13, 2016 to June 15, 2016 electric charges alone or $111.72 for total bill.
  • $61.87 for June 15, 2016 to July 14, 2016 electric charges alone or $100.17 for total bill.
  • $67.81 for July 14, 2016 to August 15, 2016 electric charges alone or $109.36 for total bill.
  • $69.72 for selling three SRECs on August 30, 2016. $23.24 each. In less than 10 months, the value of SRECs went from $158.39 to $23.24. They are worth about 15% what they were.
  • AS OF SEPTEMBER 1, 2016, MY PHOTOVOLTAIC SOLAR PANELS HAVE OFFSET THEIR COST BY $22,885.77 - $834.65 = $22,051.12. Note that their total cost is $34,625. This is based on $22,885 for 16 Sunpower panels on garage plus $10,140 for 10 Suniva panels on house. What's the deal with the $834.65? This is SREC money generated since July 19, 2013 earned by my solar water heater. It yields a fixed 2.256 SRECs per year. The first panels became operational on December 7, 2010. This means that after 5 years, 9 months, and 25 days, my photovoltaic solar panels are 64% paid for.
  • $66.03 for August 15, 2016 to September 15, 2016 electric charges alone or $106.60 for total bill.
  • $36.48 for September 15, 2016 to October 14, 2016 electric charges alone or $60.92 for total bill.
  • $45.91 for October 14, 2016 to November 14, 2016 electric charges alone or $75.49 for total bill.
  • $44.34 for selling three SRECs on November 29, 2016. Compared with my sale on December 3, 2015, the value of SRECs has dropped over 90% in less than a year.
  • $27.31 for November 14, 2016 to December 14, 2016 electric charges alone or $46.74 for total bill.
  • $20.10 for December 14, 2016 to January 14, 2017 electric charges alone or $34.92 for total bill.
  • $13.59 for selling one SREC on February 27, 2017.
  • $47.86 for February 13, 2017 to March 14, 2017 electric charges alone or $79.40 for total bill.
  • $49.73 for March 14, 2017 to April 13, 2017 electric charges alone or $81.06 for total bill.
  • $41.34 for April 13, 2017 to May 12, 2017 electric charges alone or $70.95 for total bill.
  • On May 17, 2017, we received a check for $4.61 as a result of surplus electric generation. This is something BGE does at the end of April each year.
  • $58.10 for May 12, 2017 to June 15, 2017 electric charges alone or $97.71 for total bill.
  • $14.58 for selling three SRECs on June 8, 2017.
  • $54.02 for June 15, 2017 to July 14, 2017 electric charges alone or $90.97 for total bill.
  • $51.39 for July 14, 2017 to August 14, 2017 electric charges alone or $86.78 for total bill.
  • $47.72 for August 14, 2017 to September 15, 2017 electric charges alone or $81.14 for total bill.
  • $37.26 for September 15, 2017 to October 14, 2017 electric charges alone or $64.44 for total bill.

  • Future
    The 16 panels, inverter, and installation cost me $24,485. That's more than I've ever spent on a vehicle. So you'd better believe I called up my insurance company and asked them to increase the coverage on my garage. It's only an extra $40 per year and well worth it for the peace of mind.

    The cost for the garage work and the solar panels almost wiped out everything in my savings and checking accounts. If I only save $568 per year on electricity, then why bother? Because if all works according to plan, I will get
  • $7345 back (30%) as a federal tax credit
  • $1840 back as a state grant
  • $5000 deducted from Howard County property taxes (after being put on a 2 year waiting list). Living in Howard or Montgomery Counties make the cost of solar much cheaper than living in other counties. But sadly, as of 2012, Howard County no longer offers any incentives for geothermal or solar. So much for the county, which in 2011,
    was ranked the third wealthiest county by median household income in the United States by the U.S. Census Bureau.
    - from Wikipedia - Howard County, Maryland
    It is interesting how one of the richest counties in the country isn't willing to support environmentally sustainable choices. Anyway, as of July 3, 2012, I was told by Jason Brown of the Howard County Property Tax Division that I would see my property tax credit next year.

  • This means that assuming I get all the money that is due to me, the net cost is $10,229.50.

    But it is estmated that I will get $1800 back annually from SRECs over the next few years. Hence, according to Solar Energy World, the system on the garage should pay for itself in just(24,485-7345-1840-5000)/(555.66+1800) = 4.37 years, using 2011 Dominion energy rates. Compare this to replacing our very old freezer, which is NOT energy efficient. Even with incentives from BGE taken into account, replacing our old freezer with the cheapest, new, Energy Star rated freezer would take 5.4 years to pay for itself at the February 2011 $0.0919 per kWh rate. See attic insulation - energy efficiency.

    At the time, $1800 annually for the sale of SRECs might have seemed reasonable. But as of September 2013, that amount is unreasonably high. For 12 SRECs generated from December 7, 2010 to August 29, 2013, I earned $1094.54 + $252.96 = $1347.50 which averages out to $112.29 per SREC. 4776 kwh were generated in the first year which means if this 2010-2013 rate continues, I can expect to earn 4776/1000 * $112.29 = $536.23 annually from the sale of SRECs. This is only 30% of the estimated amount at the time I purchased my panels. Very sad.

    If the SRECs maintain their 2010-2013 value, then the system will pay for itself in (24,485-7345-1840-5000)/(555.66+536.23) = 9.43 years. If SRECs become worthless, then the system will pay for itself in (24,485-7345-1840-5000-1347.50)/555.66 = 16.11 years. Realistically, the return on investment (ROI) will be between the two, probably leaning towards the former.

    One thing that was not considered by Solar Energy World was the increase in the resale value of my property. According to Econ 101: Solar panels increase home values, photovoltaic solar panels increase home values by 3.5% in California. But keep in mind that this study was done using data in California...and not just any part of California but San Diego and Sacramento, which are known for being extremely sunny. Conversely, according to a now broken link from 2011 called Do Solar Panels Increase Home Value? real estate agents in the less sunny San Francisco area have a different opinion.
    "My experience has been that [solar panels] do not add value...the sales price on two [homes with solar] I sold did not increase in spite of heavy marketing about the panels," said David Bergman, Silicon Valley real estate agent with Intero Real Estate Services.

    How would Maryland compare? My guess is that when it comes to solar panels, we have more in common with San Francisco than Sacramento or San Diego.

    In the spring of 2013, I got more photovoltaic panels on the roof of my house. See house panels.

    Later, in September 2013, I read in the "2013 Maryland Tour of Solar and Green Homes" booklet that
    Experts estimate that the value of a property with a photovoltaic system is increased by 20 times the yearly electricity savings.
    Unfortunately, this was a blanket statement...not one that was specific to a particular region. But if we assume that it is correct, my home will have increased in value 20 * ($556 + $350) = $18,120 as a result of the photovoltaic solar panels. This accounts for the 16 panels on my garage installed in 2010 and the 10 panels installed on my house in 2013.

    I have considered getting photovoltaic panels for my rental townhouse. But the problem (as of 2011) is that rental properties are not eligible for the 30% federal tax credit. But I am eligible for a tax refund since it is a business expense. But this means that for a $32,292 system, instead of getting back $9688 as a federal tax credit, I would only get $6458 (20%). Other incentives include
  • Maryland Solar Energy Grant of $2760
  • Anne Arundel property tax credit of $2500
  • Solar Renewable Energy Credit (SREC) of $1874.40 per year
  • Estimated decrease in cost of electricity of $1022 per year
  • Taking all this into consideration means the payback for such an investment is 7.1 years. If I qualified for the 30% federal tax credit, this investment would pay for itself in 6 years and be a more viable choice.



    Enegy storage

    If the power goes out, we lose power because we are still dependent on the utility company.

    What about living off the grid? Here in Savage, that just isn't practical. Our power doesn't go out often and when it does, it usually isn't for long. We have a generator and while yes, that does use fossil fuel, we probably only average a gallon per year or less.

    But suppose we did want to store our own energy. As of 2013, batteries are still expensive, have very limited life, and are not the most environmentally friendly things when they need to get disposed of. Other options worth investigating are compressed air and flywheels.

    Compressed air energy storage systems can be built without rare materials, and can also be built to last a very long time, if the manufacturer chooses to do so. Compressed air energy storage systems can also be recharged and discharged very quickly. Some consider it “low-tech” due to its simplicity.
    - from Compressed Air Energy Storage To Grow Dramatically Over The Next Decade

    With an efficiency of more than 80 percent, it [flywheels] would rival the best storage alternatives, and come with a 10-year guarantee. And it would make a perfect complement to an off-grid house with a solar photovoltaic (PV) system, able to charge fully in five hours—within the charging time of most solar PV systems—and store 15 kilowatt-hours of power, enough to run a modest house from sunset to sunrise.
    - from Turn Up the Juice: New Flywheel Raises Hopes for Energy Storage Breakthrough


    Solar hot water heating
    How can we reduce our energy consumption further? Well, for starters, our water heater uses an estimated 4950 kWh per year. If electricity costs $0.119 per kWh (as it does from BGE in November 2010), then this equates to $589 per year. Or, if electricity costs $0.0919 per kWh (as it does from Dominion in January 2011), then this comes out to $454.91 per year. So obviously, this is a huge user of energy. According to a BGE Home folder I received, water heating accounts for 14% of the average person's $2200 energy bill.

    Heating our water with solar thermal panels is something I am currently considering. But there are many factors.

    There is no more room left on the south side of the garage so the best place for them would be on the south side of the house, which gets some shade in the morning. But before installing them, our 20 year old roof would need to be replaced. If we were to get a new roof now, without consideration for the solar panels, we could simply have a layer of shingles put over the existing shingles since there is currently only one layer. But if we got a new roof in preparation for getting solar panels, then the existing layer would need to be removed and the underlying wood inspected for structural integrity. This would cost $4200 if we went with HomeFix, the parent company of Solar Energy World. Perhaps some of this cost could be deducted from my taxes?

    The system I would purchase would likely be the Schuco Slim Line OG-300 Package II-80 with two collectors. Total cost would be $8500 and include an 85 gallon storage tank, all plumbing, a thermal control unit, a system controller, all necessary labor/materials, and all permits/inspections/applications.

    If all works according to plan, I will get
  • $2550 back (30%) as a federal tax credit
  • $1500 back as a state grant
  • $1500 deducted from Howard County property taxes (after being put on a 3 year waiting list). Eventually this was done away with...the tax deduction, not the waiting list.
  • Also, I have been told that Maryland is working on a renewable energy credit for solar thermal systems.

    The net investment for such a system would be $2950. But I (or we) would need to front $12,700 for the roof and the solar thermal system.

    According to Schuco, the average percentage of water heated by solar energy (for an electric backup system) is 66%. This means our annual energy savings for such a system would likely be 0.66 * $589 = $388 (assuming $0.119 per kWh) or 0.66 * $454.91 = $303.27 (assuming $0.0919 per kWh). If we assume the latter, then the system will pay for itself in $2950/$303.27 = 9.7 years.

    If the state implements a renewable energy credit for solar thermal systems, then this option would most certaily be attractive.

    So for now, I will wait...at least until I really need a new hot water heater.



    The above was written around 2011. In 2013, I took the plunge into buying a solar thermal system. See Water Heating.