Photovoltaic technologies are beginning to appear more attractive than concentrated solar thermal plants. PV’s competitiveness is improving from technical and operational advancements, as well as...
Solar Tech Outlook
Manufacturers scale up for utility applications.
attributes, and some of them have parts of the overall equation in place, but for a utility looking for a reliable technology that is working at utility-scale, I think you have to say thin-film PV is the proven option.
Hall, Borrego Solar Systems: Generally we believe that photovoltaic technology represents the best option for utility-scale solar generation. Just a few years ago, many wrote PV off as an option for utility-scale generation as a result of the high upfront capital cost. Two things have happened since then that I believe had led many to reconsider, and for PV to move to the top in terms of viable technology. First, is that the cost of the PV modules has dropped by 50 percent since Q3 2008. The drop was a result of increased availability of poly-silicon—the feedstock material—both because of increased production and slower rise in demand. The second thing that has happened is that the investment tax credit (ITC) has received a long-term extension. This tax credit allows an investor to recoup 30 percent of the upfront investment. PV is an ideal technology to take advantage of this tax credit as it has substantial up-front capital cost, but has lower ongoing operation cost and risk—expenses that don’t go into the tax-credit basis.
Within the PV umbrella of technologies, the market share will go mostly to standard efficiency crystalline photovoltaic modules—produced by many of the world’s top 10 PV producers—and thin film. To date, the CdTe technology has emerged as the dominant player. Amorphous silicon technologies seem to be having a harder time competing as a result in the sharp decline in price for crystalline PV.
All in all, PV has emerged as a competitive priced low-risk technology. Ultimately it will take a large portion of the utility market share that many thought would go to solar thermal.
Woolard, BrightSource Energy: We’ve selected to use a power tower approach for our solar thermal plants because the technology offers cost, efficiency and environmental advantages.
Our decision to use a power tower stems from our engineering team’s experience designing and building the nine Solar Electric Generating Stations (SEGS) in California between 1984 and 1990. These nine plants still represent more than 80 percent of the commercial solar thermal energy produced in the United States today. While built durably, the SEGS plants’ trough technology has efficiency and cost limitations that are solved during the evolution to the Luz Power Tower (LPT) 550 technology.
The power tower approach is simple—thousands of mirrors track the sun in two dimensions and reflect the sunlight to a boiler sitting atop a tower. When the concentrated sunlight strikes the boiler’s pipes, it heats the water inside to more than 1,000 degrees F. This superheated steam is then piped from the boiler to a standard turbine where electricity is generated. To conserve water, the steam is air-cooled and piped back into the system in a closed-loop, environmentally-friendly process.
Our LPT 550 technology consistently achieves more megawatt hours per MW of installed power equipment. It’s more efficient and cost effective than other solar