Ausra, a new solar thermal startup backed by the illustrious venture firms Khosla Ventures and Kleiner Perkins, just announced the closing of a $40M+ financing round from these backers.
The company, originated in Australia and now in the Bay Area, has a novel technology approach that ideally will make parabolic trough concentrator solar thermal technology obsolete. The technology is essentially the same as traditional parabolic trough technology, with mirrors focusing incoming sunlight onto a linear pipe containing a high heat capacity fluid. The fluid is then pumped to a central boiler where the heat is used to make steam and run a steam turbine to provide electric power.
The novel part is that they have taken the "parabolic trough" part out and replaced it with compact linear fresnel reflector technology. Fresnel basically means that it achieves the same focusing onto a line as a parabolic trough, but using a flat reflector with features on it designed to mimic the focusing effect of a 3D trough reflector in 2D. See this pic for a feel.
The company claims it can deliver 10.4 cents/kWh electric power now and projects that it will be able to do 7.9 cents/kWh in three years. (Are these costs or long term contract sale prices? Somebody help me here.)
Centralized solar thermal is being sold in many corners as a superior option to distributed photovoltaics, mainly in terms of cost.
However, in any given electric power market, photovoltaics, in that they deliver power on the retail side, should be given a cost "advantage" equal to the delivery (non-generation) costs of power. According to my latest NStar Electric bill, I was charged 10.8 cents/kWh for generation and 7.4 cents/kWh for delivery. So lets give PV an 8 cent/kWh advantage in discussions comparing it to solar thermal, at least in NE, for the sake of argument.
I typically hear PV levelized cost numbers of 20-50 cents/kWh, depending on the resource, interest rate, etc.
If we take Ausra at their word then, PV should be at or below 18 cents/kWh to compete with Ausra now and at or below 15 cents/kWh three years from now.
What are truly reasonable PV cost numbers these days? What are projections (given expected growth rates and learning curve behavior) 3 years, 5 years, 10 years out?
Solar thermal or PV. Weigh in!!