President-elect Joe Biden’s decision to nominate Jennifer Granholm — former governor of Michigan, lawyer, politician and television host — to be the next secretary of energy is curious.

The idea circulating is that her primary assignment, in Biden’s mind, will be to speed Detroit’s development of electric vehicles.

That is hardly the job Granholm will find confronting her when she heads to the 7th floor of the Forrestal Building, a bare-and-square concrete structure across from the romantic Smithsonian Castle on Independence Avenue in Washington.

Secretary of energy is one of the most demanding assignments in the government. The Department of Energy is a vast archipelago of scientific, defense, diplomatic and cybersecurity responsibilities. Granholm’s biggest concern, in fact, won’t be energy but defense.

The DOE, nicknamed the Little Pentagon, is responsible for maintaining, upgrading and ensuring the working order of the nation’s nuclear weapons. A critical launch telephone will go with her everywhere. That is where much of the department’s $30 billion or so budget goes.

The energy secretary is responsible for the largest scientific organization on earth: the 17 national laboratories operated by the department. They aren’t only responsible for the nuclear weapons program but also for a huge, disparate portfolio of scientific inquiry, from better materials to fill potholes to carbon capture, storage and utilization; and from small modular reactors for electricity to nuclear power for space exploration.

The national labs are vital in cybersecurity, particularly to assure the integrity of the electric grid and the security of things like Chinese-made transformers and other heavy equipment.

The DOE has the responsibility for detecting nuclear explosions abroad, measuring carbon in the atmosphere, making wind turbines more efficient, and developing the nuclear power plants that drive aircraft carriers and submarines. The department makes weapons materials, like tritium, and supervises the enrichment of uranium.

DOE scientists are looking into the very nature of physical matter. They have worked on mapping the human genome and aided nano-engineering development.

Wise secretaries of energy have realized that not only are the national laboratories a tremendous national asset but they can also be the secretary’s shock troops, ready to do what they are asked — not always the way with career bureaucrats. Their directors are wired into congressional delegations, including California with Lawrence Livermore; Illinois with Argonne; New Mexico with Los Alamos and Sandia; Tennessee with Oak Ridge; South Carolina with Savannah River.

Verifying the START nuclear weapons treaty with Russia falls to the DOE as will, possibly, renegotiating it. Another job would be being part of any future negotiations with Iran over its nuclear materials. Likewise, the energy secretary would be involved if serious negotiations are started with North Korea.

An ever-present headache for Granholm will be the long-term management of nuclear waste from the civilian program as public opposition to the Yucca Mountain site in Nevada is adamant. Also, she will be responsible for vast quantities of weapons-grade plutonium in various sites, but notably at the Pantex site in Texas and the Savannah River site in South Carolina before it is mixed with an inert substance for burial in Carlsbad, New Mexico.

Then there are little things like the strategic petroleum reserve, the future of fracking, reducing methane emissions throughout the natural gas system, and bringing on hydrogen as a utility and transportation fuel.

DOE has been charged with facilitating natural gas and oil exports. Now those are subject to the objections of environmentalists.

Smart secretaries have built good relationships early with various Senate and House committees that have oversight of DOE.

James Schlesinger, the first secretary of energy, led the new department with a knowledge of energy from his time as chairman of the Atomic Energy Commission, a knowledge of diplomatic nuclear strategy from his time as director of the CIA, and a knowledge of defense from his time as secretary of defense.

The only other star that has shone as brightly from the Forrestal Building was President Barack Obama’s energy secretary Ernie Moniz, a nuclear scientist from MIT who essentially took over the nuclear negotiations with Iran: He and Iranian negotiator Ali Akbar Salehi, a fellow MIT graduate, hammered out the agreement, which was a work of art, a pas de deux, by two truly informed nuclear aficionados.

Compared to the awesome reach of DOE in other vital areas, electric cars seem of little consequence, especially as Elon Musk with Tesla already has scaled that mountain, and all the car companies are scrambling up behind him.