Former U.S. Department of Energy Secretary Ernest Moniz on Nov. 8 laid out his top three clean energy investment priorities during an episode of Market Intelligence Live.

Moniz delivered his remarks as climate negotiators are meeting is Glasgow, Scotland, and countries like the U.S. are urging other top global greenhouse gas emitters to set climate targets in line with a 1.5-degree C warming scenario by the end of the century.

Moniz noted climate commitments announced at the crucial United Nations-hosted climate conference will materially lower the kind of post-industrial temperature rise scientists have long warned about. The professor, who has a deep background in energy technology and is professor emeritus at the Massachusetts Institute of Technology, also singled out several areas where climate-minded investors could look to allocate capital as the energy transition continues to play out.

Firm power

"Clearly, wind and solar, which are variable, are going to play tremendously important roles," Moniz said during the interview. "But I think there's now a realization that one is going to also need firm power at scale."

Moniz said technologies that enable existing power plants to capture and store their carbon emissions could represent one opportunity. Another is facilities capable of long-duration, seasonal energy storage.

"I don't mean eight hours versus two hours," Moniz said. "I mean days, weeks, and potentially even seasons."

Green hydrogen could play such a role in gas-fired generation, Moniz said, "which can address many different industrial sectors' energy needs."

Nuclear, Carbon Capture

Moniz also highlighted recent innovation in nuclear technology, saying that "we've had more innovation in this last decade than ever before." Generation IV reactors, which include high-temperature gas reactors and molten salt reactors, "have a lot of very attractive characteristics." But he acknowledged that the costs of the technology need to come down.

Nuclear fusion, a long-term, sustainable form of energy that largely avoids radioactive waste issues, has also come a long way in recent years, Moniz said. "I flat out expect that the scientific case for fusion will be answered in this decade," Moniz said. "That's not the same thing as having engineered plants, but I'm pretty bullish that the answer will be positive."

Also "absolutely essential," according to Moniz, is finding ways to "remove legacy carbon dioxide from the atmosphere and the upper levels of the ocean.

United Nations estimates for a 1.5 degree C warming scenario assume a massive deployment of technologies such as direct air capture, which sucks CO2 out of the air and stores it underground.

"Direct air capture is the most talked about, but there are many other approaches including what we call technology-enhanced natural solutions," Moniz said. Those include accelerated mineralization to absorb CO2, he said.

EPA authority

Moniz also weighed in on the U.S. Supreme Court's recent decision to review the U.S. Environmental Protection Agency's authority to regulate power plants for greenhouse gas emissions under the Clean Air Act.

The high court is in the midst of reviewing legal challenges brought by coal-producing states and coal companies seeking an answer to the question of how far the agency can go in regulating electric generators under an ambiguously written statute.

"EPA regulation in the electricity space is absolutely critical for the kind of deep decarbonization of electricity that the president has mentioned," Moniz said.

U.S. President Joe Biden is aiming to completely decarbonize the nation's power sector by 2035.

Watch a replay of the interview on YouTube.

To read all of our coverage of COP26, click here.