A "trilemma" persists for U.S. energy: no single source perfectly balances reliability, affordability, and cleanliness, according to the new report’s chapter on energy. Technologies reviewed include iron-air batteries for long-duration storage, green hydrogen, enhanced geothermal energy, and small modular nuclear reactors.

Researchers have created an ultrathin silver coating for solid electrolytes that increases resistance to cracking, promising breakthroughs in the safety and longevity of lithium metal batteries.

Entrepreneurial timing – among other ingredients – in cleantech can make or break a venture, says William Chueh, director of Stanford's Precourt Institute for Energy, in the debut episode of the new Stanford Ecopreneurship Podcast (and vodcast).