It’s been a while in the making but the solar panels for the well pump have finally been mounted!

The panels are 285 watt polycrystalline units from GC, a Chinese manufacturer since since 2006.

They are 77″ x 39″ x 2″ and weigh 26 Kg each. We installed 3 panels for now and connected them in series.

We felt that we got a reasonable deal at $90 each and invested in 5 panels, so there are 2 spares.

Electrical Specs are as follows:

Voc     44.21     V
Isc           8.27   A
Vmp   36.79     V
Imp       7.76     A

The 110.37 volts they can develop in full sun is adequate to power the Grundfos 11-SQF-2 pump and CU-200 controller. At 7.76 amps, they generate as much as 856 watts, well below the maximum power input recommendation for the pump. This system includes solar panels only. No batteries, charge controller or inverter required as the pump runs on DC current. Of course, the drawback is that it will only pump during the day.

The mounting frame was constructed mainly of hardware purchased at Lowes. The parts list is given below.

12	1/4” x 2”	Lag screws	#63350
12	1/2” x 2”	Hex bolts	#64329
12	1/2” x 2”	Fender washers	#68885
12	1/2”	Spring nuts	ZA1001/EG-10
6	1/4” x 1-3/8” x 2-3/4”	U-bolts	Stainless steel V2193
4	14 gauge	10’ Sections	Unistrut
3	1”	10’ sections pipe	Black iron
6	1”	Pipe hangers	2x #301383 (4-pack)

Note: 2 of the unistrut sections were cut to provide 6 pieces at 38-5/8″ and inserted into the panel frames for mounting struts. These were then clamped to the 2 stringers with the hex bolts and spring nuts.