2035 Grid Mix Graphs

The forecast generation mix under the 90-percent clean-energy grid versus the "no new policy" plan. 

The United States can reach 90-percent carbon-free electricity by 2035 using existing technology and without increasing customer bills, according to a new report from the University of California, Berkeley, and the energy nonprofit GridLab—but it won't be easy.

Without aggressive buildouts of renewables and strong policies at the state and federal levels, the U.S. will only achieve 55-percent clean energy by 2035, the report's authors said during a June 16 webinar hosted by Clean Energy States Alliance's 100% Clean Energy Collaborative.

To meet a 90-percent goal, the energy sector would need to invest more than $1.7 trillion in clean energy, which would create an estimated 500,000 more jobs through 2035, the report says. The lost jobs from a shrinking fossil-fuel industry would be "more than made up for" with these additional jobs, Ric O'Connell, GridLab's executive director, said during the webinar. 

The rapid decline in costs for solar, wind and energy storage make the prospect of early decarbonization imminently more achievable, Amol Phadke, senior scientist at Berkeley's Goldman School of Public Policy, said. In the 90-percent clean-energy model, the remaining 10 percent would be generated by natural gas, with the assumption that coal would be completely phased out by 2035. The report's authors further found that wholesale electricity costs, including incremental transmission costs, would be 10 percent lower under the 90-percent clean-energy model than today's costs.

The researchers used a comparative, "no new policy" model to forecast the future of energy generation without any additional state and federal intervention. Under that scenario, they found that the grid mix would be approximately half natural gas and coal. Natural gas and coal accounted in 2019 for about 62 percent of all utility-scale generation, according to the U.S. Energy Information Administration.

Getting to 90-percent renewable generation in the U.S. would require an extraordinary infrastructure buildout, however—about 70 GW per year through the 2020s. Reinstating the advanced manufacturing tax credit from the 2009 American Recovery and Reinvestment Act, for example, would be one way to support domestic production. But "investments and tax credits alone will not get us there," Mike O'Boyle, director at Energy Innovation, said during the webinar. 

A policy paper accompanying the report offers a series of state-level policy recommendations moving forward: adopting a clean-energy standard of 90 percent by 2035 or earlier; prohibiting investor-owned utilities from investing in new natural gas absent a demonstrable need; allowing state utility commissions to use ratepayer-backed bonds to securitize gas and coal units; and requiring utilities to use all-source procurements for new projects.

Many of these policies are already being adopted in California and the Southwest states. Both California and New Mexico have adopted 100-percent zero-carbon energy targets by 2045, under California's 2018 SB 100 and New Mexico's SB 489, passed in 2019. The New Mexico Public Regulation Commission authorized the sale of ratepayer-backed bonds, as outlined in SB 489, by Public Service Company of New Mexico to fund the closure of units 1 and 4 of the coal-fired San Juan Generating Station near Farmington (see CEM No. 1584). The passage of HB 19-1314 in Colorado, which sets up a "just transition office" to support communities impacted by coal plant closures, is suggested in the report as a potential model for other states moving forward.

The report also argues that a 90-percent clean-energy grid would be reliable throughout the day without large supplementary coal or natural gas assets, particularly given steep declines in battery storage prices. The price of lithium-ion batteries has fallen by about 80 percent since 2015, according to a Jan. 2 blog post by the National Renewable Energy Laboratory. Though renewable generation can drop as much as 70 percent hour by hour compared with average values for each resource, Phadke said, the system would be balanced with the remaining combination of hydro, nuclear, storage and natural gas. "We feel that eventually even this 10-percent gas can be replaced to get to 100 percent [clean energy], because there are several technologies in the pipeline that look promising," he said.

A policy paper accompanying the report calls on Congress to reform the Federal Energy Regulatory Commission's interconnection rules to deliver new renewable energy resources at scale. It also suggests Congress could match funds for states constructing interstate transmission lines to streamline long-distance energy delivery.

"I think we've definitively proved that this pathway is a pretty easy, straightforward pathway we can take with existing technology and relatively straightforward policy . . . Cleaning up the grid quickly matters, so we shouldn't take the approach of, 'Let's go slow,'" O'Connell said.

Aria covers California and the Southwest from Albuquerque. Her work has appeared in a variety of popular and academic publications.