Credit: Joe Flores, Southern California Edison
Solar Two located near Barstow, California uses heliostats to maximize solar gain. (All those mirror move like plants tracking the sun.) Nevada Solar One will use parabolic troughs as thermal solar concentrators.
It is difficult to believe that someone would be leaving another modern country to come to America to develop renewable energy. Given the United States current energy policy, you might think the reverse to be true. Yet, according to the Big Gav, David Mills and Solar Heat and Power Pty Ltd, are moving to America.
Given Australia is the No. 1 nation in the world in terms of available land and available hours of sunlight to develop solar energy, given Australia once led the world in solar energy research, given our appalling level of greenhouse emissions, and given one of the most advanced companies in the field of solar thermal energy is Australian, you might think this would be the place to build an industrial-scale solar power plant. But no.
The blog previously cited Australia as one place in particular that seemed to be well suited to the development of thermal solar. Indeed, it was a “Solar Energy Advisory” from the South Australia Government, which indicated that desert locations were ideal since the skies are predominantly clear throughout the year.
Whereas photo voltaic systems are suited for providing household power or supplemental power for larger sites, the cost of PV systems still prohibits large scale usage by utility companies. On the other hand, thermal solar has a comparitively quick ROI (Return On Investment) compared with PV. And, while the retail price and initial plant construction costs of solar thermal energy are higher than more traditional power plant construction, according to David Mills “once carbon emissions and energy inputs are accounted for, then solar thermal power is cheaper and, obviously, incomparably cleaner over the long term.”
The departure of an advanced technology company from Australia in part may be on account of the current Australian government favors coal and nuclear options. Yet it also could be the attraction of demonstration projects, such as the one that has stimulated thermal solar development in the Southwest United States.
Illustration from Arizon Public Service
Solar thermal power systems use solar-generated heat to drive an engine or turbine connected to an electric generator.
With signifcant help from the U.S. Department of Energy and its National Renewable Energy Laboratory, Southern California Edison was able to demonstrate the cost effectiveness of a CSP (Concentrating Solar Power) installation competitive with traditional load-following / peaking generation. Now several other Southwestern utilities are investing in thermal solar, albeit using parabolic trough collectors.
Parabolic mirrors concentrate solar energy onto thermal receivers containing a heat transfer fluid. A heat transfer fluid is circulated and heated through the receivers, and the heat released to a series of heat exchangers. Parabolic trough solar technology thus converts sunshine into useful thermal energy and, by concentrating the heat, generate super-heated steam. The steam powers a turbine/generator to produce electricity.
There are two, parabolic trough, solar power plants located in Spain, each with 50MW capacity and one 500MW plant in Israel. (The Israeli company is building another plant in Spain.) Still, the United States and China are the more power hungry nations in the world and where the best, current opportunity is seen for CSP development.