History In early 2008 I thought it would be cool to have a residential vertical access wind turbine on my house generating electricity. For a few months I had an anemometer installed to capture wind speeds; after four months' worth of data, we came to the conclusion that there just wasn't enough wind in Washington, DC to justify the cost of the wind turbine. (In other words, it might likely never pay for itself!) In Feb. 2008 I started attending the Capitol Hill Energy Cooperative. The speakers were fantastic, the information was great, and I was sorry that because of consistent scheduling difficulties I had to stop attending. When the wind turbine idea flopped, I asked Energy and Environment, Inc. to provide some price quotes on a solar array. (They were the same company who put up my anemometer.) I had become increasingly interested in renewable energy and the 30% federal tax credit really seemed to make the system affordable. In addition, I learned that for each 1,000kwH of energy that I produced I would received a Solar Renewable Energy Credit (SREC). That SREC could then be sold on the open market. (My system should generate about 4-5 SRECs each year.) On Sept. 4, 2009, my solar array was finally turned on. It is a 3.78kw system that consists of 14 SunTech 270 panels coupled with a Fronius IG inverter. In addition, I have a Personal Display inside my house to view real-time energy production. Finally, I also installed a Fronius Datalogger Web, coupled with a Linksys wireless bridge, that updates my energy productions in real-time to the inverter's website. The system is expected to generate roughly 4,674kwH per year, which is about 72% of my home's energy needs.  Pictures The pictures below are captured in chronological order.                           This is the solar inverter (on the left) and the emergency cut-off switch (on the right). If you look closely you can see a little item protruding from the right of the solar inverter; it communicates wirelessly with the “Personal Data Display” inside the house   Oct. 6, 2009 - As mentioned before, the solar system shuts itself off at night. Look above and see this value: "1.107kW", which is the same as 1,107W. When this gets down to, say, 50W or so, the system will shut off for the night. That happens around 6:15pm and the system starts back up around 7:40am.          Thus, the solar system has generated 714kwH; in addition to that, I have used an additional 157kwH. 714kwH + 157kwH = 871kwH used. Therefore, the system has generated 714kwH / 871kwH = ~82% of my needs. [It's probably 1-2% lower because I didn't receive the digital meter until 14 days after the solar panels were turned on.]     Jan. 25, 2010 - The system has surpassed 1,000kwh. That means that I have will receive a "Solar Renewable Energy Credit (SREC)". This will allow me to sell it on SRECtrade.com. My guess is that I'll get about $250 for it. The current meter reading is 00447; above shows 1,004kwh. 1,0004kwh + 447kwh = 1,451kwh consumed between Sept. 4, 2009 and now. 1,004kwh / 1,451kwh = 69.2%. That means that so far the system has generated 69.2% of the house's needs. Jan. 30, 2010 - I was concerned that getting my 30% federal tax credit was going to be difficult. So far it seems pretty easy; I simply typed in the total amount of the system into taxcut.com (which I've been using for years):  ...and then voila! The next screen shows my federal tax credit:   Jan. 31, 2010 - January has been a fairly good month; so far January created 195.8kwH. (Today and yesterday are not so good because of the snow.)
Feb. 21, 2010 - The current meter reading is 00712. The solar panels have produced so far 1,126kwH. 712 + 1,126 = 1,838. 1,126 / 1,838 = 61%; therefore, so far the panels have produced 61% of the house's energy needs. Big drop from before but for six days (Feb. 6 - 11) nothing was produced due to the massive snowstorms we had (and thus which covered the solar panels). Today and yesterday were very good days, though: yesterday produced 13.3kwH and today produced 12.87kwH. March 24, 2010 - Today has been the best solar day yet! 18.57kwH of energy was produced!   The current PEPCO meter reading is 00659. So far the solar panels have produced 1,473kwH. 659 + 1,473 = 2,132. 1,473 / 2,132 = 69.1%. That means the panels have produced 69.1% of the house's energy needs since installation (Sept. 2009).
March 30, 2010 - Below you'll see my PEPCO bill for the period Feb. 23 - Mar. 23, 2010. Note that it shows a previous meter reading of 721 and a current meter reading of 666.  April 22, 2010 - The current PEPCO meter reading is 00513. So far the solar panels have produced 1,883 kwH. 513 + 1,883 = 2,396. 1,883 / 2,396 = 78.6%. That means the panels have produced 78.6% of the house's energy needs since installation (Sept. 2009). In addition, yesterday I received payment for my first SREC:  As I get an SREC for every 1,000 kwH produced, and I've already produced 1,883 kwH, I should be getting another one soon. :-)
April 30, 2010 - The PEPCO electricity bill arrived: just $9.84 (fees and taxes) and you'll note that PEPCO correctly showed the negative balance!  Note that as of last night, my PEPCO meter reading was 00478, which is about the same as around the end of January 2010. May 11, 2010 - Today's PEPCO meter reading was 00444; the panels have produced in aggregate 2,183kwH. Therefore: 444 + 2,183 = 2,627kwH. 2,123 / 2,627 = 83.1% of the home's needs have been met by the solar panels! :-) August 1, 2010 - It's been hot recently so the air conditioning has been running near constantly for the last month. The panels have been producing about 17-20 kwH per day. Today's PEPCO meter reading was 01928; the panels have produced in aggregate 3,433kwH. Therefore: 1,928 + 3,433 = 5,361kwH. 3,433 / 5,361 = 64% of the home's needs have been met by the solar panels. Aug. 31, 2010 - Today's PEPCO meter reading was 02483; the panels have produced in aggregate 3,838kwH. Therefore, 2,483 + 3,838 = 6,321kwH. 3,838 / 6,321 = 60.7% of the home's needs have been met by the solar panels. Not as high as I would have liked, but the last two months have indeed been very hot, so the air conditioning has been running nearly constantly. Sept. 3, 2010 (Final, end-of-the-first-year tally) - Today's PEPCO meter reading was 02591; the panels have produced 3,878kwH. Therefore, 2,591 + 3,878 = 6,469kwH. 3,878 / 6,469 = 59.9%. Lower than what I had expected, but this summer has been hot (a lot of air conditioning), and for a good 10 days in winter, due to the snow on the panels, not a lick of energy was produced. Let's hope it starts to cool down soon and I can turn off the air conditioning! Feb. 23, 2011: Below are screenshots of my PEPCO bill:
  March 31, 2011: The recent PEPCO bill is below:
  April 4, 2011: I haven't updated recently in terms of usage but as I just received an inquiry regarding my energy usage and creation, I thought it would be a good time to do so. Today's PEPCO meter reading was 03448; the panels have produced 5,825kwH since their installation in Sept. 2009. Therefore, I have used 9,273kwH of energy between Sept. 2009 and April 2011. (Calculation: 5,825kwH + 3,448kwH = 9,273kwH.) So that means that of the total amount consumed (9,273kwH), the solar panels have produced 5,825kwH, or 62.8% (5,825 / 9,273 = 62.8%).
Also, while logged into my PEPCO account I saw this interesting run-down of payments:
 April 17, 2011: Today the panels produced 22.17kwH of energy:
 That seemed like a high number, so I scanned through the online archives of my system and I learned that today's generation (22.17kwH) is the highest ever since Sept. 2009. EVER!!! The second-highest occurred on May 10, 2010 (21.83kwH):
 April 30, 2011 - Today's PEPCO meter reading is 03372; the panels have produced in total 6,186kwH. Therefore, I have used 9,558kwH of energy between Sept. 2009 and the end of April 2011. That means that of the total amount consumed (9,558kwH), the solar panels have produced 6,186kwH, or 64.7% (6,186 / 9,558 = 64.7%).
May 31, 2011 - Today's PEPCO meter reading is 03605; the panels have produced in total 6,639kwH. Therefore, I have used 10,244kwH of energy since Sept. 2009. That means that the solar panels have produced 64.8% of my needs (6,639 / 10,244 = 64.8%). July 1, 2011 - Today's PEPCO meter reading is 04273; the panels have produced in total 7,111kwH. Therefore, I have used 11,384kwH of energy since Sept. 2009. That means that the solar panels have produced 62.5% of my needs (7,111 / 11,384 = 62.5%). What's interesting is that I just received my PEPCO bill and it shows that I produced 159kwH more energy last month than I consumed. This has happened in the past so it didn't surprise me. What did surprise me is that it actually calculated a CREDIT on my account for this amount. Note first the April 27, 2010 bill below; you'll see that I generated no CREDIT but was instead just charged the minimum Generation charge of $3.23:   Now take a look at my most recent bill from June 22, 2011 (where a credit was generated for the 159kwH over-produced):   |