Lew Hodgett wrote:

80W solar panels are less than $500.

T-105, 6VDC, golf cart batteries are less than $65.

A small inverter is less than $500.

Assume the sump pump requires 2A and operates on a 50% duty cycle
which would require 240W/hour.

I use 50% efficiency of solar cells for estimating, thus (80W)50% =
40W.

240W/40W = 6 panels or about $3,000.

T-105 are rated about 235AH.

If you cycle them between 70%-90%, they provide about 47AH/pair at
12VDC.

240W/47AH = 5 sets of batteries minimum, I'd probably use 6 sets or 12
batteries,
thus (12)$65)=$780

Panels....................$3000
Batteries..................$800
Inverter....................$500
Misc hardware.........$500

Total......................$4800

Use $5000 as an estimate to achieve total independance from an
unreliable supplier.

Lew



A 7 KW Guardian generator runs around $2,000.

--
Jack Novak
Buffalo, NY - USA