Alcoa is testing a unique concentrating solar power (CSP) parabolic trough technology at the National Renewable Energy Laboratory in Golden, Colo. The technology could be the company’s entry point into the solar power business.
The news is important for a couple of reasons. Alcoa’s technology uses aluminum instead of glass mirrors to capture solar heat. While it may not be the first company to try this, Alcoa is certainly the largest. It’s also a vote of confidence by one of the country’s largest companies on the long-term viability of CSP technology .
For Alcoa, one of the world’s major aluminum producers, developing aluminum-based mirrors makes good business sense. They have the resources and knowledge to develop new applications for the the most abundant metal in the earth’s crust.
Alcoa says that aluminum-based mirrors are more durable and environmentally friendly than glass-based mirrors. CSP Today reports that the jury is still out, but that aluminium- and polymer-based mirrors are giving glass a run for its money.
Aluminum mirrors will “enable[s] manufacturers to more easily scale up to meet the growing demand for this solar technology, ” said Eric Winter, Alcoa’s director of development laboratories, in a prepared statement.
A company spokesman tells G.E.R. that parabolic troughs could become a full-fledged business unit of Alcoa. That’s reminiscent of General Electric’s entry into the wind turbine business over a decade ago.
CSP advocates argue that the systems are cheaper to install and operate than photovoltaic systems, but the recent dramatic drop in the price of silicon-based photovoltaic panels along with favorable incentive programs around the world is keeping photovoltaics in the running for utility-scale projects.
One advantage CSP systems offer over photovoltaic systems is that it can they can store energy in the form of heat, which is much easier and cheaper to do than storing electricity, which is the only storage option for photovoltaic systems. Energy storage for solar power systems can help project economics, because it allows the systems to store energy until electric demand, and therefore prices, are high.
Some have expressed concerns about the environmental impact of large CSP plants, such as the this California project using CSP dish-Stirling technology in flat-tailed-horned lizard territory. CSP systems require the clear cloudless skies of environmentally-sensitive deserts. Others worry about the water required for mirror washing and power plant cooling, but engineers knowledgeable about the systems claim that the water argument against the technology is overblown.
The testing of the Alcoa mirrors at NREL is partially funded by a $2.1 million Department of Energy grant — see here for the full press release.