You can’t see them or hear them, but there are huge, hidden forces propelling the United States into the energy future. Last year, the Biden administration committed to eliminating half the country’s greenhouse gas emissions by 2030, a critical step in fighting climate change. Half sounds like a lot—and it is—but scientists think it’s doable.
Different teams have modeled how exactly this decarbonization might play out—by rolling out more solar and wind energy, for example, and more electric vehicles—and landed on several paths to cutting emissions in half in the next eight years. A new paper in the journal Science took six of these scenarios and found that they share several major points: the keys to a clean-energy future. “Reducing our emissions by 50 percent is technically feasible, it's economically viable, and there are massive additional benefits,” says Lawrence Berkeley National Laboratory energy economist Nikit Abhyankar, a coauthor of the paper. “So this is what we call a no-regrets strategy.”
The first area where those scenarios agree is that we’ll have to target the power and transportation sectors. To halve emissions, Abhyankar says, by 2030 the US grid will need to be running on about 80 percent carbon-free electricity (including hydropower and nuclear power), up from 40 percent today. The good news is that we’re already heading in that direction. In recent years, the US has been making significant progress in its effort to ditch coal for natural gas power plants. Yes, that gas is still a fossil fuel that spews carbon, but not nearly as much as coal.
Meanwhile, the costs of solar and wind energy are cratering. The price of solar technology has dropped 99 percent in the past four decades. And it’s getting less expensive for homeowners and utilities to store renewable energy: Between 1995 and 2018, the production of lithium-ion batteries jumped 30 percentper year while getting 12 percent cheaper each year. Earlier this month, the California utility PG&E commissioned a battery storage system that can provide power to over 200,000 homes for four hours. For homeowners, Tesla’s (very expensive) Powerwall battery can both charge a car and power a home during an outage, providing some independence from the grid.
The bigger challenge is the grid itself. The switch to renewables is happening on ancient infrastructure designed for on-demand energy generation—if you need more electricity, you burn more fossil fuels. The US grid is also actually three distinct grids with little interconnection: eastern and western grids, and one just for Texas. That means if demand spikes in one region and the sun isn’t shining or the wind isn’t blowing there, operators can’t import large amounts of power from elsewhere. This is the intermittency challenge of renewables: They’re critical to fighting climate change, but the grid just isn’t designed for them.
But, Abhyankar says, wind and solar power has gotten so cheap, and energy extraction so much more efficient, that this may not be a big problem in the short term. Extremely efficient panels and turbines can still generate enough electricity to make economic sense, even for regions that don’t have the number of sunny days Phoenix has, or the wind the Midwest has. That opens up the option of generating green energy locally, instead of having to import it across state lines. “Contrary to the conventional way of planning the grid—where you’ll choose the best of the best resource, site the renewable capacity there, and carry that electricity long distances—that trend has started changing because of the falling costs,” says Abhyankar. “And that might play a major role up to 2030 or so.”