The U.S. Department of Energy (DOE) is providing $175 million to support the research and development of "high-risk, high-impact" clean energy technology research.

The OPEN 2021 program from DOE's Advanced Research Projects Agency-Energy (ARPA-E) will fund 68 projects proposed by universities, national laboratories, and private companies. The projects will work to advance technologies like electric vehicles, offshore wind, energy storage, nuclear fusion, and grid modernization, among other areas.

Many of the funded projects involve innovations that are intended to replace rare or expensive materials in clean energy systems. ARPA-E projects have attracted $7.6 billion in private-sector investment following $2.93 billion of R&D support by the agency since 2009. Here are a few notable projects from the latest funding round.

For the past decade, Dr. Yan Yao, a professor and researcher in the University of Houston's Cullen College of Engineering, has explored how to replace lithium with magnesium in batteries without losing power density.

Dr. Yan Yao, a professor and researcher in the University of Houston's Cullen College of Engineering

If successfully produced at scale, magnesium batteries could be used for fast-charging electric vehicles and grid storage as a 1-to-1 replacement for lithium batteries while using the same manufacturing infrastructure. Yao told Renewable Energy World in an interview that his lab's organic magnesium batteries contain no transition metals, which addresses cost and availability issues surrounding lithium, nickel, and cobalt.

Through a partnership with the Toyota Research Institute of North America, Yao's team has already demonstrated power capabilities in excess of 5kW/Kg at a small scale. The $3.4 million grant from ARPA-E will be used to demonstrate performance at a larger scale.

Traditional institutions and companies don't fund research like this, Yao said, because they're "very cautious about new technologies" that come with a high risk of failure.

"You have to de-risk to a certain level before the private funding can follow," Yao said. "That's exactly what I plan to do for this project."

The University of Illinois at Urbana-Champaign received $3 million to demonstrate an ultra-fast, efficient deicing process for aircraft and renewable energy systems using pulsed interfacial heating.

The team aims to apply the technology to photovoltaics, heap pump heat exchangers, wind turbines, and electrified aircraft.

In order to defrost, the system cooling function is shut down, and the working fluid is heated to melt ice or frost, said Nenad Milijkovic, lead author and U. of I. mechanical science and engineering professor. The working fluid then needs to be cooled once the surface is clean. “This consumes a lot of energy when you think of the yearly operational costs of running intermittent defrosting cycles," he said of the research in 2019.

The technique saves energy by melting only a thin layer of the ice or frost at the surface and allowing gravity to remove the rest, instead of warming other components of the system. As a result, this process 1% of the energy and .01% of the time needed for typical de-icing techniques, the researchers said.

Buelton, California-based SixPoint Materials (SPM) has received funding from ARPA-E multiple times since 2014, according to CEO Tadao Hashimoto. The latest funding round amounts to $1.78 million. 

SPM is developing a bulk thick crystal of semi-insulating gallium nitride for use in a 100 kV photoconductive semiconductor switch. The advancement would potentially replace 56 semiconductor switches made with conventional silicon. Doing so would significantly increase efficiency and lower cost, Hashimoto told Renewable Energy World.

The component is key in multi-terminal HVDC transmission systems, and SPM's innovation would help expand the use of renewable energy resources.

"Material advancement always results in a big impact to technologies," Hashimoto said. "People try to avoid the hard part" of redesigning the silicon wafer. Government support for new material advancements is "very important."

Hashimoto said the power-grade gallium nitride wafers have wireless, defense, and industrial applications, as well.