Right now prices per PV watt are very, very low. This is because of over production, mainly Chinese companies, and lack of demand. EU demand has dropped because of the economy and Spain, which had a very expensive subsidy, had to end the subsidy because they are broke.
So the good news is that PV costs are rock bottom. The problem is which company will be around tomorrow to provide a warranty service? GE just sold its solar business so even big names are not immune to the chaos in the PV market place. On the other hand, the panels will likely work for decades if they last a few weeks, months or years.
Whether solar makes money sense depends not only on Federal and State subsidies but also on state power regulations. In NC, the regulations as written earlier in the year, are such that it is not worthwhile to sell power back to the grid. The regulations require you to pay Time Of Use rates, lock you into certain rate periods, and does not pay much. The class I took early this year and my reading of the regulations say that you should only produce power that you will use and NOT sell back to the grid in NC.
What does that mean in numbers? I have been recording our energy usage day and night. I wish I could easily record what the power usage is from say 1100 to 1600 but I can't. That time period is very important because we only get FIVE hours of power production a day. So if we don't want to give money to Duke Energy, and I certainly do not want to give money to those lying b....ds, we have to have a system that will only produce the power we will use in that time frame. My best guess is that we would not use more than 2-3KW each hour during that time frame on a yearly basis. Lets says we would use 3KW per hour or a total of 15 KWH during that power generation time. We would have to install about 3.75 KW of panels on the roof to get 3KW at the outlets. The extra PV is for power loss in the system.
I can't remember if the yearly average monthly power bill is $120 or $140 so lets call it $130. Power costs us 10 cents per KWH. If we install solar that uses 15KWH per day for 30 days that is $45 a month which is 35% of our average power bill.
I can only guess at the COST of the system but doing some quick searches on the Internet lets say the system would cost at a $2 a watt for the parts and $1 a watt for installation. 3,750 watts * $3 = $11,250. This is grid tie so no batteries.
NC has a subsidy of 35% and Feds have 30% so EVENTUALLY the system would cost me $3,937 so lets say $4,000. Why eventually? Like so many things with solar, the details matter A LOT. NC will give you 35% of the cost of solar but this is gated by how much money one PAYS in state taxes. NC will only rebate in a given year, HALF of what you owe in taxes. So if you owe $2,000 in taxes, they will only pay you $1,000 for the solar subsidy in a given tax year. You can roll this over for either five or seven years.
Installing solar is expensive. You have to have either the cash or the ability to get a large loan to install even a small system that provides a small percentage of your power needs. If the system ends up cost me $4,000, and it saves us $45 a month, it means that the system pays for itself in 7 to 8 years. If there were NO government subsidy the payoff would be 20 years. The lifetime on the panels is around 20-30 years.
The design point was that we would use 3 KWH and thus should produce 3KWH. If we only use 2KWH and produce 3KWH we just gave Duke money.
Later,
Dan
