The Department of Energy is funding a series of projects that marry concentrating solar power with storage, which offers the potential of solar power plants that operate 18 hours a day.
The DOE said Friday that it has made $62 million available to 13 companies to test equipment and materials, such as molten salts, to add storage to solar power systems that use heat to produce electricity.
Concentrating solar power, in which the sun's heat creates steam to drive an electricity turbine, is seeing a renaissance because it can be used for large-scale power plants in deserts. Adding storage can extend the time these plants supply electricity to the grid and can potentially improve the economics of solar versus fossil fuels.
The DOE's target is to extend the output of concentrating solar power systems to 18 hours, covering the peak times of electricity usage.
The top three recipients are Abengoa Solar, eSolar, and Pratt & Whitney Rocketdyne, each of which received more than $10 million for molten-salt research.
Abengoa Solar is already operating a solar storage facility and will test a solar tower that operates at a higher temperature, which could improve the overall output for a given land area. Solar tower designs use heliostats, or mirrors that track the sun, to reflect light onto a tower to heat a liquid.
eSolar's project will seek to build components for smaller, distributed solar towers to heat molten salt. It will also test an electricity generator that operates using molten salt.
Pratt & Whitney Rocketdyne, which developed the molten-salt solar storage technology now being used by start-up SolarReserve, will test different materials and a more efficient power-conversion cycle.
The other 10 projects, which received funds ranging from $2.1 million to $4.5 million, are "feasibility studies" with the goal of creating prototypes for concentrating solar power products that can generate baseload power, or a steady supply at times of high demand.
Different storage materials, such as heated solids and sulfur, will be tested. Also, the research is aimed at lowering the cost of concentrating solar power with low-cost production techniques or alternative components.