Well its July 29th and its been hot and sunny the past month. We got our power bill today so I sat down to condense my daily/weekly reports from the solar array putting things into perspective.
Mid June – Mid July we used 3728 Kw from the grid and the solar array generated 1080Kw. Our current grid power rate was billed at 10.0cents/kw so we saved about $113. You could say were generating about 33% of our needs. Avg daily temps were 100 so the Geo units were humming away plus running the pool pump about 8hrs/day can build up a load. System total of solar power generated is over 3.3Megawatts!!!
Ive been asked over the past months how long our solar inverter batteries will carry the home so I ran a night time test. At 8pm with no sun shining I cut the grid off with the 400amp switch and manually powered up the Xantrex inverter using the 4 marine batteries. I did shut down the pool and Geo Air conditioners to see how the system handles just the bare essentials like minimal lighting, a tv, refrigerators and all that phantom power likes clocks and dvrs. Things ran smoothly for 1.5hrs without any issues. No lights pulsing or the like were seen during the test.
I did run the pool pump and the basics without any problems. The Geo well pump also runs just fine pulling an estimated 1400watts…ouch. I did not power up any Geo units for this test but will on the next. We will add another battery bank of 4 marine deep cycle batts which will double the run time. I have to watch however just how many sets of 4 I add. If I add 1 set to many the sun will take to long recharging them if I use only the sun. The Xantrex does have a setting to allow grid recharging or not. Today its cloudy so I enabled grid recharge which took a little over an hour to bring the batteries back to full charge. Atleast I know the inverter is fully working.
An update on TXU and excess power buyback (what we sell back). We received a letter a couple weeks back offering 7.5cents/Kw sold back to the grid. They also wanted my REC or Renewable Energy Credits which I didnt like. After a couple calls to TXU and saying I want compensation or strike that part from the contract I guess this created a little fuss in the office and they were going back to see what could be done. Ive read on another website they are rewriting the contract to not include the RECs which is fine if they choose not to buy them from us. Some states are buying the RECs for 13cents up to 20cents/Kw and some others offer up to $90/Megawatt.
Not much else new on the solar subject.
