Quote:
Originally Posted by JSH
We have found an alternative- steel roofs. Last time I replaced my roof it added 10% to the cost but was expected to last twice as long as asphalt.
I do want a roof on a roof. Solar panels with an air gap shade the roof and reduce A/C use in the summer.
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Quick math double-check...
Sendler said NY is 13.7% of nameplate output. PNW should be similar.
A 5,000 watt system would cost $10k if the cost is $2/W
5,000 watts * 0.137 efficiency = 16.44 kWh per day = $1.32 at 8 cent per kWh rate
That's $480 per year in electricity savings, or 20 years to recover the cost of the system, not including lost opportunity cost to invest the $10k, and not including maintenance, degradation, etc.
Even if the system could reach 20% of nameplate, that is a 14 year payback, not including opportunity cost of lost investment money. Solar may never pay back if you include lost investment opportunity.
My utility bill averages less than $40/mo, and that includes the $12 fixed cost.
Where did my math go wrong that I conclude a never payback period, when you figured a 10 year payback?