A 200-foot tower stands centered in front of a field of rotating mirrors on the southern edge of Albuquerque, New Mexico.

It’s the National Solar Thermal Test Facility, operated by Sandia National Laboratories, where scientists are working to develop hotter, cheaper, and more efficient technologies for concentrating solar power.

The hundreds of mirrors focus sunlight onto a receiver at the top of the solar tower. In conventional systems, this would heat water or other fluids to generate steam that drives an electric turbine. But here a curtain of fine ceramic particles continually falls through the concentrated sunbeam instead. The particles, which resemble black sand, can easily reach temperatures 100 ˚C hotter than those standard fluids. That promises to boost the available energy, cutting the costs of production and storage.

This approach is one of three that federal researchers believe could help concentrating solar power finally become affordable and sustainable. Last January, the National Renewable Energy Laboratory published a next-generation demonstration road map that highlighted falling particles, higher-temperature molten-salt systems, and a gas-based heat transfer fluid as promising pathways to produce solar thermal energy at six cents per kilowatt-hour by 2020, a goal set by the Department of Energy’s SunShot Initiative in 2011.

The Department of Energy announced in September that it would invest $62 million in about a dozen promising projects along these pathways, sparking renewed excitement in a field that had largely faded from the public view (see “Making Sense of Trump’s Surprising Investment in Solar”).

Researchers at Sandia, the National Renewable Energy Laboratory, Savannah River National Laboratory, and Brayton Energy have confirmed to MIT Technology Review that they’ve applied for the funds, individually or as teams. Concept papers were due earlier this month, and the deadline for full applications is mid-January 2018.