In the middle of the Nevada desert, 10,000 billboard-sized mirrors reflect sunlight onto a tower that stores the energy in molten salt–an innovative way to make solar power available to nearby Las Vegas at night . In Arizona, Fluidic Energy designs rechargeable, next generation batteries for energy storage that are in use around the developing world. In Oregon and elsewhere, the solar developer SunPower is using drones to more quickly plot the ideal configuration for solar farms, and robots to clean panels so they can absorb more sunlight.

All of these technologies got their start at least in part because of government funding, from sources that may dwindle or disappear under Trump. It raises a question: how will the current administration’s policies affect innovation in renewable energy?

The White House’s proposed budget eliminates the Advanced Research Projects Agency-Energy (ARPA-E), as does a spending bill currently in Congress. The Congressional bill also cuts funding roughly in half for the Office of Energy Efficiency and Renewable Energy (Trump wanted to cut it 71.9%). It cuts 2018 funding for energy programs in the Department of Energy by $1.7 billion compared to 2017 (Trump wanted to cut it by an additional $2.3 billion).

This is happening when the renewable energy industry is arguably stronger than it ever has been before. In 2016, more than half of all new energy installations used renewable sources. Solar and wind are now cheaper than coal power in many markets, and in about a decade, solar is likely to be cheaper than natural gas. Cleantech startups are thriving. But it’s also possible that changes in policy and government funding could slow down future innovation.

Large energy companies, who often invest in startups with new technology, typically don’t want to fund nascent innovations that aren’t already proven. “If they look externally, they’re going to look at companies that have already established themselves, that have a product that can come to market relatively quickly,” says Rohit Shukla, CEO of the Larta Institute, a company that helps commercialize technologies funded by federal grants. In the past, the riskiest new ideas might have had a better chance of getting a government grant.

“Who fills that gap is the real issue,” Shukla tells Fast Company. “There’s so much good science coming out from universities or smaller companies. And yet there’s no particular support for the first phases of bringing that technology to a particular point so that they then become acceptable and worthwhile for larger companies to invest in.”

The possibility of slower progress is worrying some of those larger companies, not just the researchers and entrepreneurs working on very early-stage technology. “I’ve been having conversations with some of the larger companies, and they’re nervous because they benefit from the cleantech startups that can take the risks they can’t,” says Eliot Metzger, a senior associate at the World Resources Institute, a global research organization. “They’re worried that this stunts their growth.”