I never understood why anyone would think small grid tie inverters are a good idea.
And I wonder how many they will sell... to save money on the electric bill.
Where I live, best numbers I can find for KWH:
In 2005 was $0.083.
In 2008 was about >$0.10.
Only real price I can find is a contract for $0.0688.
There are other charges, some fixed and some (I guess) are related to KWH used.
I read a web page about understanding your electric bill, which condensed basically said "Trust the bill is correct, or call someone who can explain it."
I can't quite figure it out so I'll say $0.10/KWH.
The PV is 175W and I'll say the inverter is 90% efficient.
Here averages about 4.5 hours of insolation.
That's 0.709KWH/day.
Or $0.070875 saved per day.
Panel costs $893. I figure DIY installation will cost about $157. $1050.
It would cost me a LOT more because it would need, start to finish, done by a licensed union electrician. That's my problem, so I won't include the cost, which would be a LOT.
Then any power company paperwork and inspection fees, building permits (which are known to increase property tax here), etc, which I won't include.
So $1050 payback is 14815 days. 40 years and 7 months.
If I was to do it totally like it is supposed to be done, probably cost over $2000.
With $0.0688/kwh, payback is well over 100 years.
G-