Analysts put price on carbonless grid
Converting the United States to a 100 percent renewable electric grid will require spending $4.5 trillion and approximately doubling the existing level of generation capacity to account for wind and solar energy’s intermittent availability, the consulting firm Wood Mackenzie reports.
The consultants estimate it would be necessary to add about 1,600 gigawatts of new wind and solar generating capacity—the equivalent of duplicating Wisconsin’s Point Beach nuclear plant approximately 1,354 times—to supplant all U.S. fossil-fueled generation.
In addition to building about twice as much new generation capacity as currently exists on the U.S. grid, decarbonization would also call for about 900 gigawatts of new storage capacity (equaling another 761 Point Beach plants) “to ensure wind- and solar-generated power is available exactly when consumers need it,” the Wood Mackenzie analysis said.
“The scale of the challenge is unprecedented, requiring a complete redesign of the power sector,” the report added.
The report is based on a six-month analysis of actual hourly wind and solar generation patterns from all major U.S. power markets, the consultants said. They indicated that achieving a 50 percent renewable power supply from intermittent renewables system-wide is “relatively straightforward in most of the U.S.”
However, once renewables are providing half the power supply, the challenges of increasing their share “accelerate rapidly,” the report said, adding that the grid’s ability to provide energy would need to be roughly doubled.
More third-party questions as PSC okays utility solar
Wisconsin’s Public Service Commission (PSC) has approved two regulated utilities expanding solar generation programs, in decisions criticized by groups arguing that regulated utilities are using monopoly status as retail energy providers to crowd out independent developers.
Commissioners voted to permit expansion of Madison Gas and Electric’s “Shared Solar” program with a new five-megawatt solar garden, and an Alliant Energy program offering residential customers opportunities to buy subscriptions at about $1,200 per kilowatt for shares in community solar gardens.
Another Alliant program, allowing the utility to install solar panels on customer properties, was approved 2–1 with PSC Chair Rebeca Valcq dissenting.
The PSC has declined to address third-party ownership of generation facilities, an alternative approach that would permit non-utility private solar developers to mount their equipment on residential or commercial properties and sell the output to the occupants at retail.
Opponents contend such transactions would put the developers in the role of regulated utilities under existing Wisconsin law, and developers argue they should be exempt from PSC regulation. The PSC maintains authority to decide those questions rests with the legislature, not the commission.
So far there’s been little indication of legislative interest in revising the definition of a state-regulated utility.