Democratic presidential candidates talked hardly at all in the debates late last month about the Green New Deal, a proposal in Congress, to, among other things convert America's electric power completely to renewable sources. Americans have shown broad support for such a transition.
What's been left unaddressed—and which many candidates weren't prepared to discuss—is the cost.
Estimates vary by trillions of dollars, but now a respected consulting firm—one that has consulted with the oil industry for decades, yet predicts a rapid rise for electric cars—has compiled an estimate of the cost of converting to 100 percent renewable power in the U.S.: $4.5 trillion, or about a quarter of U.S. GDP for 2018.
“The mass deployment of wind and solar generation will require substantial investments in utility-scale storage to ensure grid resilience is maintained," said Dan Shreve, Wood Mackenzie's head of global wind energy research said in a statement.
The firm reports that transitioning the U.S. to 100 percent renewable electricity would require building 1,600 gigawatts of new wind and solar capacity to replace the fossil fuel generation in the U.S., along with 900 gigawatts of energy storage, which could include some combination of batteries, pumped hydro, and other types of storage to buffer the intermittent power from wind and solar.
Tesla Kauai solar-energy generation and storage project [photo: Tesla]
For example, stored energy would provide power at night when the sun isn't shining and when electric cars are most often parked and ready to charge.
Wood Mackenzie doesn't make light of the transition, saying it will pose massive social and economic challenges, even if the money is spent over the next decade or two. The firm reports that the U.S. currently has about 130 gigawatts of wind and solar capacity, and says that to transition to 100 percent renewable energy would require as much new capacity every year for the next 11 years as has been installed in the past 20 years.
“The mass deployment of wind and solar generation will require substantial investments in utility-scale storage to ensure grid resilience is maintained,” it says.
Chevrolet Bolt EV charging at EVgo fast chargers at Chevron station in Menlo Park, California
It has a few suggestions that could make the transition easier. The first is to stretch the timeline to 2040 or 2050, when solar and storage technology have matured and become more affordable. California has passed a law requiring the state to transition to 100 percent electric power by 2045.
The other is to keep a certain amount of natural-gas power generation, which is relatively clean and affordable. Keeping 20 percent if existing natural gas power would reduce the cost of new renewable energy installations by 20 percent, but more importantly would reduce the need for new storage by 60 percent, because those plants could be used as peaker and base load plants to provide energy when renewables aren't.
Beyond that, a transition to 100 percent renewable power would require new financial systems to trade energy. "The challenges of achieving 100 percent renewable energy go far beyond the capital costs of new generating assets," says Dan Shreve, Wood Mackenzie's head of global wind energy research said in a statement. "Most notably, it will need a substantial redesign of electricity markets, migrating away from traditional energy-only constructs and more towards a capacity market."
To combat global warming, and for electric cars to live up to their potential, it would be helpful for the U.S. to discuss how to make such a transition. Knowing the cost seems like the first step.