WASHINGTON — The Biden administration said Tuesday that it had given the go-ahead to two major solar projects on federal land in the California desert, pushing forward with clean energy plans by using federal authority after Joe Manchin III, the West Virginia senator and coal industry supporter, this week said he would not back broader climate legislation, stalling it in Congress.

The two approved solar projects, and a third for which approval is nearing completion, would generate about 1,000 megawatts, enough electricity to power about 132,000 homes, the Interior Department said. All three projects are in Riverside County, Calif.

The project approvals are significant because they represent one of a limited number of policy tools available to the Biden administration as it works to wean the United States from fossil fuels and achieve a goal of slashing the country’s greenhouse gas emissions roughly in half by 2030.

Democrats have vowed to move forward with a vote on President Biden’s signature policy agenda, the Build Back Better Act, which includes $555 billion in clean energy tax credits. But the measure is not expected to pass given the statement this week from Mr. Manchin announcing his opposition.

Without that legislation, Mr. Biden is left with executive actions to advance his agenda. But that authority also faces challenges. In February the Supreme Court will hear arguments in a case brought by coal companies and Republican-led states to limit the authority of the Environmental Protection Agency to regulate greenhouse gas emissions.

“All bets are off with this Supreme Court,” said John Podesta, a former top aide to President Barack Obama, speaking at a recent panel discussion on climate change. “It’s definitely a challenge.”

The solar farms approved on Tuesday are known as the Arica and Victory Pass projects. According to the Interior Department, they will be photovoltaic solar projects and will generate a total of up to 465 megawatts of electricity with up to 400 megawatts of battery storage. The combined projects would cost about $689 billion to build, according to the agency, which called them an “infrastructure investment.”

The Bureau of Land Management also is expected in coming days to approve a separate 500-megawatt photovoltaic plan known as the Oberon solar project. Located on 2,700 acres of public land in Riverside County, it is expected to generate 500 megawatts of renewable energy and power nearly 142,000 homes, the agency said.

“The efficient deployment of renewable energy projects will create good-paying jobs and are crucial in achieving the Biden-Harris administration’s goal of a carbon pollution-free power sector by 2035,” Tracy Stone-Manning, the director of the Bureau of Land Management, said in a statement.

Meanwhile, the agency also said it was soliciting interest for utility-scale solar energy development on nearly 90,000 acres of public land within what it called solar energy zones in Colorado, Nevada and New Mexico. In addition to eliminating emissions from fossil fuels in the electricity sector by 2035, Mr. Biden has pledged to cut United States emissions at least 52 percent from 2005 levels by the end of the decade.