WASHINGTON – Jennifer M. Granholm, who received a confirmation hearing on Wednesday morning as President Biden’s candidate to run the Department of Energy, is widely expected to play a pivotal role in the government’s efforts to combat climate change.

However, this begs the question: how much can a Secretary of Energy realistically do to reduce US greenhouse gas emissions that are warming the planet?

The agency controls some powerful levers that could contribute to the advancement of clean energy technologies: a network of 17 national laboratories doing cutting-edge research, unused federal loan guarantees in the tens of billions, and regulators promoting energy-efficient and new device transmission lines.

But there are also major challenges in managing this sprawling, often unwieldy agency. Only about a fifth of the Department of Energy’s annual budget of $ 35 billion is dedicated to energy programs. The remainder is used to maintain the nation’s nuclear arsenal, solve cold war environmental problems, and conduct scientific research in areas such as high energy physics.

“There will be a lot of competing demands on the energy secretary’s time,” said Dan Reicher, former deputy secretary of energy under President Bill Clinton, who noted past secretaries had been grappling with oil spill or radioactive leak crises. “Even the best of plans can be disrupted.”

Here’s a look at what the energy department could do about climate policy.

There is broad consensus among energy experts that the world could use major technological advances to stop global warming, such as better batteries to handle larger amounts of solar and wind power on the grid, or carbon capture techniques to keep carbon dioxide off strong Plants trap polluting cement before it reaches the atmosphere.

In the past, the Energy Department has promoted this type of innovation, done basic research in their laboratories, and helped private companies bring risky technologies to market. The agency’s investments in shale gas technology in the 1970s laid the foundation for the fracking boom. The Obama administration’s SunShot initiative helped lower the price of utility-scale solar energy by more than 70 percent from 2010 to 2016.

Such energy innovations are usually supported by the legislature on a non-partisan basis.

In December, Congress rejected former President Trump’s request to cut the agency’s energy bills, and instead approved an additional $ 35 billion over the next decade to invest in new energy storage technologies, advanced nuclear power, and techniques to remove carbon dioxide from the country Explore and demonstrate air.

While much of this spending is being controlled by Congress, Ms. Granholm would have leeway to transform and direct the agency’s efforts. The Obama administration, for example, directed national laboratories to work on topics such as batteries for electric vehicles and recycling. In contrast, the Trump administration highlighted efforts to improve coal technology – a major producer of greenhouse gases.

“It makes a huge difference whether there is a clear direction from above to focus on tackling climate change,” said Arjun Krishnaswami, policy analyst with the Defense Council for Natural Resources, who co-authored a 2018 report on how the division could do more prioritize global warming. (The report’s other author, Tarak Shah, is the agency’s new chief of staff.)

The Department of Energy is currently empowered to stop low interest loans of more than $ 40 billion that could theoretically help bring new technologies to the market for renewable energy, nuclear power, carbon capture and storage. These loan programs have been largely untouched for years.

Mrs Granholm could revive the programs relatively quickly, although this would involve some risks.

The Obama administration used loan guarantees to support a number of novel clean energy projects and companies, including Tesla, which quickly paid off its debt and later became the world’s largest maker of electric cars. These programs also met with heavy criticism from Republicans after the agency guaranteed a $ 535 million loan to Solyndra, a bankrupt California solar company.

The Trump administration has largely suspended loan programs, reflecting the conservative view that the federal government should focus primarily on early-stage research and leave the rest to the private sector.

Still, some experts have argued that the agency could do a lot more to help commercialize promising new technologies, and the loan program could be part of that.

“There is a compelling case for government to play a critical role in reducing the risk of bringing new technologies to market,” said Erin Burns, executive director of Carbon180, a nonprofit focused on carbon removal . “But it also means being willing to take risks for things that may not work.”

For the most part, the energy department cannot require companies to lower their emissions or adopt cleaner technology – that is largely the responsibility of the Environmental Protection Agency or Congress.

There is one notable exception, however.

The energy department oversees energy efficiency standards for a wide variety of devices and equipment such as light bulbs, refrigerators, water heaters and industrial engines. The Obama administration is known to have used these standards to phase out traditional lightbulbs in favor of models that use less electricity. In contrast, the Trump administration has relaxed many of these standards that industry groups sometimes oppose.

Mr. Biden has already instructed the energy department to rethink and tighten their efficiency rules. A recent report by the American Council for an Energy Efficient Economy estimated that doing so could help the United States avoid emitting around 2.9 billion tons of carbon dioxide by 2050 – the equivalent of shutting down at least 13 large coal-fired power plants.

The Biden government has set itself the goal of eliminating emissions from American power plants by 2035. According to experts, this could prove difficult without building huge new high-voltage transmission lines to carry more electricity from remote wind and solar parks.

However, new transmission lines are notoriously difficult to build and are often rejected by local landowners. The process of funding and approving these projects can be complicated and split between different states and regulators.

In theory, the Department of Energy could play a bigger role in streamlining this process. For example, according to laws previously passed by Congress, the federal government has the authority to determine transmission corridors as in the national interest and in certain cases even to override the state regulatory authorities if the approval process has stalled.

A recent report from Columbia University’s Center on Global Energy Policy and New York University’s Institute for Policy Integrity examined how the Department of Energy and other regulators could use some of these tools to expand the national grid. The lead author, Avi Zevin, was recently hired by the Department of Energy as Deputy General Counsel for Energy Policy.

But there are also dangers: If the federal government moves too aggressively, it could lead to a backlash from states, legislators in Congress or the courts. For the most part, previous administrations have been cautious about trading here.

“Yes, the agency is there, but it can be difficult,” said Alexandra Klass, a transference specialist at the University of Minnesota Law School. “You don’t want to upset people too much or Congress could easily take that authority away.”

Ultimately, experts say, a major overhaul of the national energy system will require Congress to introduce new laws. While the Department of Energy can help develop new clean energy technologies, companies may have little incentive to use them unless governments pass new guidelines that require lower emissions.

The energy department also has a relatively limited budget. The agency currently spends about $ 8 billion a year on energy. During the campaign, Mr. Biden pledged to invest $ 40 billion a year in clean energy innovations over the next decade to pursue goals like the development of energy storage systems, which are one-tenth the cost of today’s batteries, or the emissions of Lower heavy industry.

A massive increase in funding would require Congressional approval, either as part of a post-coronavirus stimulus bill or through regular spending. That means convincing sometimes skeptical lawmakers that government can play an effective role in advancing new technologies.

“When you ask how much the Department of Energy can do, it really depends on the budget,” Reicher said. “So the question is how far Congress wants to go.”