The International Energy Agency (IEA) says CSP has a very bright future too because it enables cheap, efficient storage, which allows CSP plants to provide electricity long after the sun has set.
Solar photovoltaic (PV) systems have seen explosive growth because of their stunning 99 percent price drop in the past quarter century. As a result, the other form of solar power — concentrated solar thermal power (CSP) — is a small fraction of the solar market.
But the International Energy Agency (IEA) says CSP has a very bright future too because it enables cheap, efficient storage, which allows CSP plants to provide electricity long after the sun has set. According to the IEA’s 2014 CSP Technology Roadmap, 11 percent of global electricity will be generated by concentrating solar thermal power in 2050. In this post, I review the basics of CSP and look at how its recent resurgence portends a big future.
CSP is the use of mirrors to focus sunlight to heat a fluid that runs an engine to make electricity. One of the basic CSP designs used today is the power tower (above photo of the Crescent Dunes Solar Energy Project), which uses many mirrors moving in two dimensions to focus sunlight on a central tower that holds the engine. Another key design is the parabolic trough, which uses mirrors to focus the light on a long tube filled with a heat-storing fluid (right).
The key attribute of CSP is that it generates primary energy in the form of heat, which can be stored 20 to 100 times more cheaply than electricity — and with far greater efficiency. Commercial projects have already demonstrated that CSP systems can store energy by heating oil or molten salt, which can retain the heat for hours.
Here is a basic overview video of CSP from the U.S. Department of Energy:
What is happening right now with CSP? While market penetration has been slower than expected, in part because of the stunning price drop in PV power, CSP has begun to see significant growth.
Here is a chart of global CSP capacity from 1984 through 2013 in Megawatts:
A 2014 independent market analysis projected that the global CSP market will see “phenomenal growth at a 19.4% CAGR