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.
thermal technologies for a number of reasons. For example, by creating steam directly from the sun, we avoid the use of oil or another intermediary that can harm the environment and result in parasitic energy loss. Our heliostats follow the sun on two-axis, tracking its location throughout the day and throughout the year, achieving a much higher efficiency than other solar thermal technologies. Our plants can be fitted with auxiliary boilers, providing a reliable electricity supply during solar and non-solar hours and extended periods of solar disruption. Finally, we have lower capital costs due to commodity-based inputs; heliostat mirrors are simpler to manufacture and less costly to install than parabolic mirrors. Also, LPT requires very limited concrete foundations and fewer pipes and cabling.
LPT is also more environmentally-friendly than other solar thermal technologies. We use air instead of water for cooling—dry cooling—which reduces water consumption by 90 percent; up to 25 times less than other solar technologies. LPT’s higher temperatures allow a more efficient use of dry-cooling compared to other solar thermal technologies. LPT also has a far smaller impact on habitat and land because it places individual poles directly into the ground. By doing so, we can use land with grades of up to 5 percent, reducing extensive land grading found on sites that use other solar technologies. And because we don’t extensively grade the land, our solar fields allow vegetation to co-exist within the plant. The technology also allows us to follow the land’s natural contours, limiting disruption to sensitive habitat and ecosystems.
King, Canadian Solar: Crystalline silicon currently provides a proven track record of performance and bankability due to its established position in the solar marketplace and overall simplicity of installation. It’s the most cost-effective product option for utility-scale solar installations.
MacDonald, Skyline Solar: Because government incentives are so important in determining cost of a solar project, the answer really depends on where the project will be located. What’s true everywhere, though, is that risks are minimized with scalable projects that can be funded and brought on-line in manageable phases. The lower risk profile of concentrating PV is—or should be—much more attractive to utilities than high-risk concentrating solar thermal projects. A 50-MW CPV plant can be built and interconnected in five to 10 phases, whereas a similar-sized CSP plant would have to be built and funded as a single project. The permitting and land acquisition issues are much more manageable with a phased approach.
Fortnightly: What utility-scale projects is your company presently involved with?
Hall, Borrego Solar Systems: We’re working with a number of clients on the development of utility-scale projects. Our role in most of those projects is that of a consultant or co-developer. Our EPC business is primarily focused on distributed generation projects, but we have a consulting business that helps developers with technical and financial feasibility for larger scale projects. Most of the utility-scale projects we’re working on are 5- to 50-MW solar farms using crystalline silicon PV technology.
Woolard, BrightSource Energy: We’re actively developing a number of sites—more than 4 GW worth—in the U.S.