Let’s say I built a 100 megawatt photovoltaic power plant in Blythe, in a hot desert. The same 100 megawatts in 1,000 commercial rooftops in San Diego … you would pay a bit more. However if you’re building that array out in the desert, you need to transmit it in. You need transmission to do that.
One of my main arguments against doing it in the desert is that the utilities, like SDGE make their best rate of return on new transmission lines, like the Sunrise Powerlink that’s been so controversial here. So a utility is almost reflexively saying we must put it out remotely in order to get the most cost-effective power. But if you add the cost of putting in that transmission line you’ve completely negated the economic benefit.
And, addressing another point, yes, the solar intensity in Blythe is 10 to 15 percent better than it would be on average in coastal San Diego, but the amount of losses that transmission line will incur — especially on a hot summer day when you’re trying to deal with your peak loads — is also in the 10 to 15 percent range.