SB-1, California’s hot topic million solar roofs bill, lost out last month. A definite setback to the solar industry here. I’m personally in favor of the solar roof bill, but some of the analysis around it was a little odd.

A couple of months ago a solar company called Akeena, put out a whitepaper saying that if California adopted the Million Solar Roofs Bill that it could save over $6 Billion over and above the costs of the $ Bil subsidy. Akeena WhitePaper.

They were quoting $9 Billion in benefits for $3 Billion in incentive costs over 10 years. They estimated total system costs at roughly $7/watt, and projected declining subsidies.

Most of the “savings” was projected from $7 Bil avoided cost of building new infrastructure, both generation and T&D, with smaller amounts $0.5 Bil from emissions reduction and $1.5 Bil from new jobs and taxes. The amounts were calculated over a 10 year basis. The main driver is that avoided cost for new generation and T&D.

What I didn’t understand at first was that the report calculated the benefit of the full avoided cost for new generation and T&D capacity that we would skip by adding 3,000 MW of solar capacity, but the cost side of the equation only seemed to include the subsidy, or STATE’s portion of the total solar bill. Each company or homeowner that put in a system would pay thousands of dollars more in costs as well. When you include that in the equation, the numbers don’t look so good, and probably show a small net gain at best, and more likely a net loss, over 10 years.

It seemed to me the analysis only included half the cost, while adding all the benefits.

The reality check is simple, the payback for a homeowner putting in one new solar system is 25 years with no subsidy, 16 with the state’s subsidy, by the report’s own analysis. So it’s really hard to believe analysis saying that if we subsidize putting in 1 million homes, instead of one, then we as the state can get 3x our money back in 10 years. The answer: we can’t, not if we include ALL the costs.

This all said, I still the like the million solar roofs idea. California is a green state and should be at the forefront of alternative energy. We’ve put our money where our mouth is before when it comes to the environment, and we can again, but I like to know how much I’m paying.