If you're anywhere near Boulder, CO, it's hard not to be over-run with news about renewable energy, green energy, or as some like to purport 'free-energy
'. I'm all for playing a bit nicer with the environment around me, but I always turn to the spreadsheet to ask 'is it really worth it?' before believing anything I read on the internet (kind of like you are now)...
So I whipped up this spread sheet
. Please take a look and tell me what I'm doing wrong. I included the sources for all my numbers. I would be shocked dead with a heart attack if my shoe-box apartment used anything near as much as 9000kWh per year, but it's a number to start with. SparkFun does have the benefit of having a Solar supplier
, but anyone can actually search out a supplier
(yeah internet!). Also, a 5kW system is a rather large PV (photovoltaic) array. I want to believe many home installations are smaller than this.
What is interesting is the rebate offered by Xcel
(our local energy company). $4.50 per DC Watt is astounding. Without this rebate, the number of years to pay back $21,000 worth of solar panels would be over 22 years! The average panel life is 15-25 years. So as long as there is a hefty rebate (I'll believe it when I see it), we should cover every square inch of our roof. That is if you want to reduce your electric bill. Powering your car on solar energy
is another calculation entirely.