Earth Day 4.22.09

Well its Earth Day Apr 22, 2009. I don’t know if its  going to get a lot of press we are going to do our part and document it right here.

At 10am central I will disconnect our Oncor grid connection and run the home completely on solar pv.  Weather is  going to be sunny and 93′  here in Fort Worth Tx.  so the test of the foam insulation, UV tinted windows and geothermal A/C will pay off.

I will post times and home status below during the day as my time permits. Solar production below is what the home is only requiring electrically from the solar arrays.

Time:   Outside:   Inside:          Solar production:    Oncor grid:

08:30     Sunny 65′    Kit72,Attic64   Shade – 118 watts    Connected

09:45     Sunny 71′    Kit73,Attic73   50%sun- 815 watts   Connected

10:03     Sunny 73′    Kit73,Attic76   90%sun-1015 watts   Disconnected

12:05     Sunny 82′    Kit74,Attic88   100%sun-1751watts   Disconnected

15:07    Sunny 90′    Kit74,Attic93   100%sun-1626watts   Disconnected

17:03    Sunny 92′    Kit75,Attic98    100%sun-2015watts  Disconnected

17:10  We went back on grid before the sun’s angle gets too far to the west.

All in all..things went pretty good today without the grid.

On another subject tho I’ve learned the TXU who is our local REP or Electric reseller of Oncor power hasn’t got there act together with the Net-Metering customers and its 40+ days past the original deadline of March 15th.  This means that in our case all the excess power we pushed back to Oncor/Txu didn’t credit us for our current bill.  Tho we reduced our usage overall approximately 83Kw is in limbo uncredited back to me.  I’m told TXU management wants to make sure they do it right but they knew this was coming last year and already they blew the deadline.

From reading other forums it seems I’m not the only case in North Texas and probably not the last.

Green Mountain Energy tho does have it in writting and is crediting customers Penny for Penny.

Guess Im making a call to the PUC next week to see if I have any ground to file a complaint.

Earth Day 2009

On April 22, 2009 in observance of ‘Earth Day’ we were going to  disconnect our electric grid and power our home completely by our new solar PV 6KW system but in testing the system 2 days early we can generate more than we consume so it makes sense to push clean power back into the grid than to simply not use it.

In a test today 10am, with full sun, 90% of the system was in full sun.  Grid disconnected we use about 14-18amps with basic loads. Testing of the pool kicked it up to 28amps needed, Geothermal A/C without pool put us at about 45amps.  The battery was being used a little but it never drained them.

By 1130am the panels had full sun and the batteries were charged 98%.  I connected back to the grid and waited for the inverter to sync up ( 300 seconds delay ).  While waiting I watched the outside meter which took about 20seconds for a full rotation. When the solar was back online the meter took about 10seconds to spin backwards proving we are making more than we need under normal load.

This shows us that if the grid fails we can support ourselfs with everything we need just fine. We will have to share the power with the heavy items like the AC, Pool or Oven on a one at a time basis but everything else, lighting, frigs, PCs, TVs, Washer/Dryer will be working just fine when the sun shines.  If we feel that increasing our battery run time into the PM hours or cloudy days is a concern then we will have to invest in a larger battery bank as right now its only 650amps.

Solar Array2 Done!

I took off Good Friday to work on array 2  as bad weather was heading our way for the Easter weekend.

Since I had the racks ready I ran out a guide string for the lower row to keep things lined up best as possible and started the bottom row. My dad came up to help install the last 15 panels which really only took us about an hour & half.  The clips from Unirac do speed things up vs having to screw the panel frames to the racks.  Since this rack is in running up and down vs side to side Ill have to come back next week and make a couple of minor adjustments to level a couple rows perfectly with the adjacent row.

Saturday I spent the day connecting up the wiring strings and tie wrapping everything to keep it clean.  Last was the final connection to the E-panel inside the garage and triple checking my voltages from the arrays. Each array without a load on them is producing 91volts at the racks and 89volts dc at the inverters input.  With the last check I powered up the system and waited for the countdown of the inverter to complete.  I set the remote to Sell power and the invert started humming big time.

About a minute in tho the PV breakers tripped and shutdown so I had a problem. After looking things over and watching breakers tripping I placed a call to Mid-Nite solar and left Robin a voicemail with the issue.  Not expecting a call since it was the weekend my phone rang back in 5min with Robin on the line.  He went over my wiring and hardware list and said I needed to make a change to my PV wiring as the charge controllers were fighting for the full load and tripping.  A quick trip to Home Depot and quick change to the wiring and things started once again.  This time the power up worked and the Xantrex showed 4800 watts being produced !!  Thank you Robin for calling me back else it would have been a long quiet weekend waiting for Monday.

I checked my TXU meter and now it was really going backwards, by the end of 3 hours it had already sold back 3Kw excess and my daily peak report showed 5.9Kw max output.  Next week is to be sunny so Ill have some really good numbers.  I also was stopped by a neighbor we know asking if that was solar. They want me to visit there home and see if they can also install solar for them as they think they have a south facing roof with space.  Its good that poeple want to do this and it does give you a good feeling of independence.

Solar array #2

I started work this last weekend on array #2 rack system.  Due to space limits I had to do this rack differently using whats called a hi-profile tilt system. I also didnt use the Unirac tilt legs due to unexpected costs so I compromised with super-stut at home depot.  It did take more time to setup and seasonal adjustments will take longer but it was also less than 1/2 the price.  If I find it takes to much of my time or effort I can swap the legs for Hi-profile unirac legs at a later time.

15 panels will mount on the 5 sets of racks making what will be one very nice huge array.

Array #1 went online March 20th and for the 11 days my report said:

preceeding 2009/04/01 00:26
Monthly energy harvest is 142.6 kWh
Peak power for month is 5.549 kW at 2009/03/28