How long does the energy generated by relatively good photovoltaics take to match the energy used to create..?

Question

;.. them

Answer 1

Small PV panels go for $5 to $8 per watt. 365 days averaging 8 hours of sun a day (optimistic) would yield 3 kWh per year per watt of panel capacity. About 35 cents per year while it cost you 8 bucks. So you need 23 years to recoup the initial cost and that doesn't count the batteries, invertor, controller nor installation labor.

I know you asked about energy input versus energy savings, but cost is a pretty good approximation of that. It captures the labor, raw materials and manufacturing costs of the product (all of which consume energy) and balances it with the electric grid whose price captures fuel usage, labor requirements, transmission losses, etc.

If solar companies ( http://www.planitsolar.com/html/packagedsystems.htm ) don't promise better than 15 to 25 pay-back times. And they are definitely spinning all numbers in their favor.

PV panels make the most sense when the utility is far away or unavailable. Then they can compare favorably.

Answer 2

the payback is about 1/3 to 1/2 the lifespan.
some people say it will take years like it is too much.
are they greedy? like they want free energy NOW and not have to pay anything for the solar cells?

to me if you can put up a solar cell that lasts 30 years and will pay for itself in 10, with 20 years of free power after, thats a good deal!
besides this is only if electricity does not get more expensive
if rates go up (which they will) then the people making their own power will have fixed cheaper costs and the ones buying power will have to pay whatever

Answer 3

It will take years just to recover the cost of the purchase let alone the energy to create them.