I've been quietly following these discussions so far - while I think that utility Solar is a good thing, that hopefully will be widely implemented, for me, rooftop has a much more personal impact.
For utility I pay whatever the utility can get away with, and I get the 'satisfaction' that it isn't killing the planet so fast. For rooftop I know exactly what I paid (I have both a system I have owned for 9 years, and an additional SCTY leased system) and I know exactly how much less power I have bought from the utility over the years and hence how much I have saved. In both cases the savings more than compensate for the cost - the owned system is easily paid off now, and the leased system saves me approx $60 a month going into the future.
So, for me, they are both attractive options, but a very distinctively different financial model
The problem is that your savings are being subsidized by everyone else using your utility. If you have followed the discussion you would know that the power generated on your roof is 4 times as expensive as solar power generated from large projects. The utility isn't earning a 75% profit margin, but a 10% profit margin, less than SCTY will earn if they recieve money for the duration of the contract. SCTY is able to undercut the utility in states where they recieve free service from them through net metering. In states where there is no net metering they would lose a lot of money if they tried to offer the same deal.
If everyone had solar on their roof they would have to pay the actual price, and then you would end up paying much more than you do now through the utility. An easy way to understand it is by the thought experiment of say California was 100% residential solar, would electricity be cheaper or more expensive?
The answer to that question is very simple. As I have explained before there are 3 costs to delivering power to the consumer on demand. Electricity generation, load balancing and distribution. Already when looking at electricity generation the winner becomes very obvious as large scale projects are able to sell power for 3.7c/kwh, while SCTY is selling rooftop solar power for 15c/kwh (with an escalator making it even more expensive).
Distribution is around 16% of the cost, so perhaps 2c/kwh. Lets say with rooftop solar it is half the price because we don't need the extra bit of reach of the grid to the large projects. This is very generous but it won't make a difference anyway, even if it was free.
Balancing demand and production is clearly expensive as there is still a significant gap between the costs we know utilities have and the 2 parts we have gone over. This might be around 5c/kwh at present for the utility. Now for the residential solar model where 100% of the power is from solar, the production is much more concentrated, fast most power will be generated during a 6 hour window during the day, this will add cost to this part of the cost structure as we want the production to match the consumption.
All in all the residential solar model is 15c/kwh for generation, 1c/kwh for distribution and more than 5c/kwh for load balancing, that is more than 21c/kwh, probably around 25c/kwh, so double the current utility cost.
These are all facts, you can look everything up from SCTY's PPAs to the cost structure of utilities.
@Foghat
Are you not going to give an answer to my last post? Is it because it's harder to beat around the bush when talking tangible cost?