My Home Solar Power Project

I have received a grant from the Wyoming Energy Office to help with construction of a 4KW Solar PV Grid-Intertied system.
Research suggests the most efficient idea is to use 20 higher voltage (30v) solar panels with micro inverters instead of a two strings of 12 low voltage (18v) panels wired in series (200+ volts DC, not easy to work with) and one big inverter. The micro inverters cost slightly more up front, but any failure of a panel or inverter only loses 1/20th of the output, not 1/2 or 100% (in the case of inverter failure). Also, all the panel/micro inverter pairs operate at the panel's MPPT (Maximum Power Point Tracking) value, but a string of series connected panels connected to one large inverter all operate at the output of the lesser of all the panels (the one covered with snow?).
8/9/2010:  I have ordered the panels, inverters, and most rack parts.
8/9/2010:  I have also mowed the area where the panels wil go and around the utility pole.
8/10/2010: I have temporarily staked out the panel corners to see how much space is required.
8/11/2010: Wyoming One Call notified for utility locates.
8/12/2010: Phone and Gas locates done.
8/13/2010: Receipt and shipping info have been received. Scheduled delivery is 8/18.
8/18/2010: Pallet of panels, Racks, and Inverters delivered.
9/9/2010:  Got a verbal quote from Borderline Fencing for setting posts and pouring foundations.
9/13/2010: Ordered remaining rack mounting parts, met Isaac at Wholesale Solar.
9/23/2010: Reciept for last parts order received. Scheduled to ship 9/23.
9/23/2010: Filed building permit application with Laramie County. Permit in 7-10 days.
9/23/2010: Priced pipe from Valley Steel, will probably pick up the steel next week.
10/4/2010: Picked up building permit from Laramie County.
10/6/2010: Kreuzer started foundation pier work. Drilled 24 holes, lined with gravel for drainage.
10/11/2010: Unloaded steel pipe for piers and framing.
10/15/2010: Started cutting 3" pipe for piers and installing in foundation holes.
10/18/2010: Finished getting all 3" pipe posts plumb in the holes ready for concrete.
10/18/2010: Pier inspection by county inspector, passed.
10/18/2010: Poured concrete piers around pipe posts.
10/22/2010: Began cutting and assembling the remaining panel support framework. Very slow work.
10/25/2010: Ordered 2" pipe brackets for installation of panel mounting rails.
11/1/2010: Sent Interconnection agreement to High West Energy.
11/6/2010: Finished assembly of second complete framework. Two down, two to go.
11/7/2010: Time change from MDT to MST, no more working after work. Weather also turned very cold and snowy.
11/21/2010: Finished assembly of all frames and rack mounting rails.
12/6/2010: Took a vacation day to install panels and inverters, but 50MPH winds prevented that. Picked up WEEB grounding washers from SED in Denver instead.
12/11/2010: Sent payment to High West for meter installation. I forgot it with the interconnection agreement.
12/13/2010: Installed all 20 Inverters on the mounting rails, too windy to handle the panels.
12/14/2010: Installed all 20 panels. Trenched conduit from power pole to east end of panels.
12/19/2010: Added risers, junction boxes, and disconnect switches to conduits at end of panels.
12/23/2010: Pulled wiring into place in both conduit runs. Ran cables from last inverters to junction boxes.
12/23/2010: Connected jumper cables, temporarily between sets, need larger conduit to bury.
12/23/2010: Luke Steege, Steege Electric & Construction installed disconnect box on meter pole and made all electrical connections to panel junction boxes.
12/23/2010: Installed, but did not yet register, Enphase Envoy system monitor.
12/23/2010: 2:25pm turned system on for the first time. 2:30pm modules begin to show connected to Envoy. 2:39pm panels all producing power, 3150 watts total.
12/23/2010: 4:28pm inverters all show 'DC Power too low' events. Done producing power for today.
12/24/2010: 7:16am inverters all power up. 7:40am all modules producing power, 1330 watts right now. Sun is very low still, I am suprised. 9:00am power is up to 2225 watts.
12/27/2010: Contacted Laramie County Planning Dept. Will inspect later today.
12/29/2010: Made corrections to satisfy County Inspector. Contacted to get inspected again.
12/30/2010: Inspector passed system, still wants 2" conduit between sets of panels buried. I will do this as soon as the weather allows. Called High West to get new meter.
01/04/2011: Net Meter installed by High West.
05/30/2010: Installed new conduit and longer jumper cables and buried conduits between panels.
01/19/2012: $65.42 from High West for 2392 excess kWh produced in 2011.
02/05/2013: $84.04 from High West for 2903 excess kWh produced in 2012.
01/15/2014: Replaced one failed MicroInverter.
12/05/2015: Replaced another failed MicroInverter.
08/24/2016: Power production update: 2013 = 2717 kWh, 2014 = 2661 kWh, and 2015 = 2479 kWh more than I used for that year.

To view power production click here: 

Here are some photos of the installation.

Future Solar Site, looking west.

Piers poured
All 4 sets of piers poured, view looking southwest.

Firest framework done
First framework completed. This is looking northeast.

All inverters installed, looking northwest.

All panels installed, looking northwest.

All panels installed, looking southwest.

All Done. Looking Southwest.

All Done. Looking Northeast.

Not much energy on days like these.

Energy Links

Enphase Energy Micro Inverters
Trina Solar Solar Panels
Home Power Magazine
Wholesale Solar
Solar Electric Distributors
Mr. Solar
National Renewable Energy Laboratory (NREL)
Sandia National Laboratories
Let's Go

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