Concentrated Solar Power (CSP) places #25 on Drawdown’s list of climate solutions. Scaling up CSP to 4.3% of global electricity production by 2050 would avoid 10.9 gigatons of carbon dioxide. While implementation costs of CSP are high, at US$1.3 trillion, net savings by 2050 could total $414 billion, with lifetime savings of $1.2 trillion.
Known also as solar thermal electricity, CSP produces power using a system of curved or angled mirrors to concentrate huge amounts of direct sunshine, known technically as direct normal irradiance, or DNI, then harness the resulting energy to produce steam and turn turbines.
While “optimal locales range from the Middle East to Mexico, Chile to Western China, India to Australia,” Drawdown states, a 2014 study in the journal Nature Climate Change found that the Kalahari desert and the Mediterranean Basin, particularly Spain, “have the greatest potential for larger, interconnected networks of CSP, with the potential to supply power at a cost comparable to that of fossil fuels.”
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“With advances in transmission lines, they could supply local populations and export power to places where CSP is more constrained,” Drawdown adds.
While CSP deployment has been slowed by the rapid acceleration of ever less expensive solar photovoltaics (PV), concentrated solar may soon have its own day in the sun, since the technology possesses the very thing that PVs have desperately needed until now: energy storage. “Unlike PV panels and wind turbines, CSP makes heat before it makes electricity, and the former is much easier and more efficient to store,” Drawdown notes. Because it is “more flexible and less intermittent than other renewables, CSP is easier to integrate into the conventional grid and can be a powerful complement to solar PV.”
Widespread deployment will depend on increasing the energy efficiency of solar thermal plants, as well as making their expensive mirror arrays more affordable. Experts are confident these improvements are within reach.
More vexing may be the reality that “the use of heat often implies the use of water for cooling, which can be a scarce resource in the hot, dry places ideal for CSP.” The other concern is that “by concentrating channels of intense heat, CP plants have killed bats and birds, which literally combust in midair.” At least one company has figured out how to avoid such tragic fallout from human ingenuity, and “spreading that practice for mirror operation will be critical as more plants come on line.”