Rooftop solar generators, electric vehicle batteries and other small energy resources will be allowed to supply wholesale power markets in the US, in a challenge to top-down delivery systems controlled by electric utilities. New rules approved by the Federal Energy Regulatory Commission on Thursday put these dispersed energy resources in competition with big power plants –   potentially hastening investment in solar and storage projects installed at homes and in businesses. The order on “distributed energy resources” is the latest supported by Neil Chatterjee, the Republican chairman of Ferc, to reflect the changing patterns of generating, transmitting and distributing  electricity.

“DERs can hide in plain sight in our homes, businesses and communities across the nation. But their power is mighty,” Mr Chatterjee said. As examples, Mr Chatterjee cited rooftop solar arrays, home storage batteries and “demand response,” where customers are paid to reduce their consumption, thereby subtracting demand from the power grid. Electric vehicles could be tied together by an aggregator while they are parked and plugged in, he said, effectively becoming a large battery that could feed the grid at certain times.

down costs in our markets and bolster grid resilience. That’s to say nothing of the added benefit of emissions reductions we could see from increased EV deployment,” Mr Chatterjee said. Thursday’s order builds on a policy that already allows energy storage facilities to sell into power markets. Groups of state regulators and utilities lost legal challenges to the 2018 storage rule, arguing that Ferc had overstepped its jurisdiction.

The order will allow companies to bundle electricity and other services from thousands of individual sites and sell it into Ferc-regulated wholesale markets such as PJM Interconnection, which extends from Chicago to the east coast, or into California’s market.  Mr Chatterjee cited studies forecasting up to 380 gigawatts of distributed energy resources could come online by 2025. US power plants now have about 1,100GW of generating capacity in total.