Sprawling wind farms in Wyoming. A huge solar factory expansion in Georgia. Lithium mines in Nevada. Vacuums that suck carbon from the air in Louisiana.

Over the past three years, companies have made plans to invest more than $843 billion across the United States in projects aimed at reducing planet-warming emissions, driven by lucrative tax credits for clean energy provided by the 2022 Inflation Reduction Act.

But only about $321 billion of that money has actually been spent, with many projects still on the drawing board, according to data made public on Tuesday by the Clean Investment Monitor, a joint project of the Rhodium Group and the Massachusetts Institute of Technology.

Now, much of the rest, about $522 billion, will depend on action playing out on Capitol Hill. Starting on Tuesday, Republicans in Congress will begin a contentious debate over proposals to roll back tax credits for low-carbon energy as they search for ways to pay for a roughly $4 trillion tax cut package favored by President Trump.

A draft bill issued on Monday by Republicans on the House Ways and Means Committee would effectively end most of the Inflation Reduction Act’s tax incentives.