A nuclear physicist who served as Mr. Obama’s second energy secretary remains in the running to return to his old post. Dr. Moniz, now president and chief executive officer of the Energy Futures Initiative, a research organization, served as an informal adviser to Mr. Biden during the campaign and several people who worked under him at the Energy Department said they would be thrilled to do so again.
But Dr. Moniz has detractors. Liberal groups have protested some of the positions he has taken since leaving government, including a post on the board of Southern Company, an electric and gas utility company. They also objected to his endorsements of nuclear energy and carbon capture and storage as ways to fight climate change because they believe climate policy should focus only on renewable sources like wind and solar.
Though his biggest legacy is helping to secure the Iran nuclear deal, Dr. Moniz played a key behind-the-scenes role in the Paris Agreement on climate change as well, working to make clean energy a core part of the accord. Under Mission Innovation, a parallel agreement to the Paris deal, 19 nations and the United States agreed to double research and development spending on carbon emissions-free energy. President Trump effectively backed out of the pact when he abandoned the Paris Agreement.
Also in the running:
Arun Majumdar
Dr. Majumdar, who currently is heading Mr. Biden’s transition team for the Energy Department, could become its secretary. Dr. Majumdar moved to the United States from India to earn a doctorate in mechanical engineering from the University of California, Berkeley, and went on to become the first director of Energy Department’s Advanced Research Projects Agency-Energy program, where he tried to build strong relationships with Republicans as well as Democrats. Currently Dr. Majumdar leads the Precourt Institute for Energy at Stanford University.
Elizabeth Sherwood-Randall
One of the earliest female Rhodes scholars, Ms. Sherwood-Randall has a deep background in nuclear weapons, the largest part of the Energy Department’s work, as well as challenges to the country’s electric grid. A former adviser to Mr. Biden when he was in the Senate, Ms. Sherwood-Randall served in both the Clinton and Obama administrations working on foreign policy and national security issues. From 2014 to 2017 she was the deputy secretary of energy, leading the National Nuclear Security Administration. She also headed up an initiative to address challenges to the power grid.
White House Climate Change Coordinator
Ali A. Zaidi
Mr. Zaidi, New York State’s deputy secretary of energy and environment, is widely considered the front-runner for the role of domestic climate change coordinator. The new position would require someone who could work with cabinet secretaries and other high-level figures like Mr. Kerry. Mr. Zaidi served as associate director of the White House Office of Management and Budget under Mr. Obama where he helped design the White House Climate Action Plan, a blueprint for cutting emissions.