Former vice president Joe Biden will be the next president of the United States, after securing the needed electoral votes in key swing states to defeat incumbent President Donald Trump. The Democratic candidate made clean energy and climate change a central part of his campaign, promising to spend $2 trillion on the energy transition in his first term.

That spend is a stretch in a political system as polarized as the one in Washington, D.C., however. It remains unclear whether the Republican party will hold onto its majority in the Senate, with two runoff elections in Georgia likely to determine which party is able to set the agenda in the upper chamber of Congress. If Republicans maintain control, it will make any significant climate or clean-energy related legislation a non-starter. Instead, Biden will have to rely on executive actions and compromises to advance his agenda.

Biden’s plan includes investments in research and development, reaching 100 percent clean electricity by 2035 and $400 billion for federal procurement of renewables, batteries and electric vehicles, among other policies.

His campaign has already pledged to pursue executive actions including rejoining the Paris climate agreement — which the U.S. officially exited on Nov. 4 — and reorienting the federal government’s energy purchases around clean resources. The administration could also regulate greenhouse gases under the Clean Air Act, select a Democrat to chair the Federal Energy Regulatory Commission, set building efficiency standards and require corporate climate disclosures. 

Of course, any of those moves would be subject to legal challenge, which could end up at a Supreme Court dominated by conservatives after the confirmation of Justice Amy Coney Barrett.

An uncertain path for clean energy legislation

Legislative action would be more enduring. But without a majority in the Senate, Democrats’ options on that front could be exceedingly limited. A bipartisan bill that could win overall support is more likely to feature clean energy policies tucked in among a larger package.

In a Biden administration, expanding tax credits is a top priority for the solar and wind industries. Those tax credits generally have bipartisan support, even if they’ve rarely been prioritized.

SunPower CEO Tom Werner said an extension of the investment tax credit is the company’s number one policy goal, and that some extension is still feasible under a split federal government. Gregory Wetstone, president and CEO at the American Council on Renewable Energy, also cited refundability of renewables tax credits and delaying their phasedown in the coming year among the post-election priorities of the group’s members, in part to boost an economy suffering from the coronavirus.

Stimulus legislation will be an early priority for Congress, and Biden has expressed an interest in tying clean energy to pandemic-related stimulus. Republicans and Democrats struggled to reach consensus on any stimulus legislation ahead of the election. But it’s possible that they could agree to clean energy measures, such as investments in carbon capture and storage and clean energy infrastructure funding, as part of a broader goal of revitalizing economic activity. 

ACORE also cited the need for significant new transmission infrastructure as a longer-term necessity to reach the buildout of renewables that Biden has promised.

A reversal on Trump-era policies

The range of actions available to the Biden administration will be much less far-reaching than environmentalists had hoped for if Democrats fail to capture the 50 Senate seats that would allow Vice President Kamala Harris to pass the deciding vote that could carry party-line tie votes on key legislation. But the president will have power to reverse some Trump administration environmental rollbacks, such as reduced efficiency standards and weakened emissions regulations.

While Trump’s presidency stalled and reversed momentum for federal clean energy and climate policy, renewable energy has continued a steady climb over the past four years despite those actions.

Both wind and solar grew significantly in the last four years, edging out a notable amount of coal-fired power. Wind became the largest source of renewable electricity last year, and the country’s installed solar capacity has more than doubled during Trump’s presidency.

The same dynamics of falling costs, economies of scale and increased embrace of clean energy goals by states and utilities are expected to drive continued growth for renewables, with or without federal legislation. But if Republicans maintain control of the Senate, that may set some bounds on how significant that growth can be and whether lawmakers can connect it with greater action on climate change.

In keeping with the U.S. Constitution, Biden is slated to be inaugurated on January 20.