Halotechnics – Molten Glass Thermal Storage Could Mean 6 Cent Solar

These allow much higher temperatures than have been used to date to store the heat in solar thermal power plants so they can produce power at night. This will greatly improve the efficiency and lower the costs for solar thermal power.

This is a first. While practically every other day we hear about efficiency innovations that will lower the costs of PV solar, this is a major innovation for solar thermal.

Unlike solar PV which makes electricity directly, solar thermal makes heat that runs turbines driven by steam. So, unlike solar PV, it has the potential for night time solar generation, because thermal is steam-turbine-driven energy, so it can store the days heat in molten salt solutions for tapping later as needed. This evening peak hours flexibility is its advantage over (now) cheaper PV.

Improving energy storage would reduce the cost per kilowatt-hour of the electricity produced by a solar-thermal plant, because the turbines and generators can produce power for more hours, more cheaply, if the temperatures can be kept high enough. Being able to store energy at higher temperatures is the key to cutting the costs of solar thermal, and that is what Halotechnics has pioneered.

“To hit that six-cent goal, or get close to it, you have to go to a higher-temperature system,” says Mark Mehos, manager of the National Renewable Energy Laboratory’s  Concentrated Solar Power program, in Golden, Colorado. ”The systems that are commercial today are limited to about 565 °C—that’s the molten salt tower plants,” says Mehos. “The tower and optics themselves can hit higher temperatures, but you’re limited by the salt temperature right now.”

Halotechnics was a spin-out from a chemical screening company Symyx (now a part of 

“Without an amazing ability to screen samples, it’s an intractable problem. That’s what we’re trying to do with our high-throughput technique,” says Justin Raade, CEO of Halotechnics.

The materials they have devised, which include new mixtures of salts as well as new forms of molten glass materials, could be key to making solar-thermal power plants cheap and reliable enough to compete with fossil fuels on a large scale.

The U.S. Department of Energy’s 

Halotechnics not only met but surpassed that 700°C goal: one of their new molten glass materials can work at temperatures up to 1,200 °C, says NREL’s Mehos.