Read this website about tax credits,
DSIRE: DSIRE Home.
NC gives a 35% credit and the Feds give a 30%. Your power company may also provide credits.
Read the small print though for your state if they give credits. In NC you will almost certainly take years to get the full credit since the state will only credit a maximum of 50% of the state taxes you paid. You can roll over the credit for years until the system is paid off.
To get the credit from the state, the system has to be installed by a licensed company. It is NOT a DIY installation if you want the credit. I think the power company has the same requirement.
Figure an installed cost at $6-8 a watt for a grid tied system not using batteries. The price has been dropping but the last time I websearched that is the prices I found. If you find cheaper let us know.
Home Power magazine had an article that said that you will only get 65% of the power generated on the roof into your power outlet. That seems like a HUGE amount of loss to me.
Our house uses, on average, 41 KWH per day and our area gets 5 hours of good sunlight a day. If we put up a 5,000 watt system we would generate 25KWH and the system would cost $30,000-40,000. If the loss is really 35% then we would only be generating 3,250 wats or 16 KWH or 40% of our house hold needs.
Eventually the system would cost us $10,500-14,000 after tax credits came in but we would have to have enough cash or take out a loan to buy the system at $30,000-40,000. We would have to have a loan for the better part of a year before the Fed tax credit kicked in and paid us 30%. Then the state credits would take years to roll in.
Oh, by the way, a grid tied system DOES NOT work during a power outage. You would think there would be a way to work around this but I have not found the way. So if you want back up power you need batteries. Ching Ching goes the dollar. Some of the batteries I was looking at were $250 a piece and I would need 6-8 of them. They might last 2 to 8 years. Nobody really knows. So lets say the batteries lasted four years. Every four years I would have to replace $1,500-2,000 worth of batteries which is $31-41 a month in batteries. $30-40 a month is about a third of our average power bill.
Best case, meaning the system cost $6 a watt and we actually got 100% of the power generated at the outlets, the payoff is 12 years not including interest paid on the loan required to buy the system. Worse case the system would take 24 years to pay off if the cost is $8 a watt and we only get 65% of the power generation to use. If batteries are used it really is ugly money wise.
Later,
Dan