Electric-grid operators around the country are warning of the possibility of blackouts as businesses convert to renewable energy sources.

“I’m concerned,” MISO Chief Executive John Bear told the Wall Street Journal in a piece published on Sunday. “As we move forward, we need to understand that installing a solar panel or a wind turbine is not the same as installing a thermal resource.”

The state’s system operator told the Wall Street Journal that extreme heat and wildfires might cause an energy deficit in California this summer. With MISO warning of capacity concerns that might trigger power disruptions, the Midwest could experience similar problems.

The problem is spreading across the country as numerous traditional and nuclear power facilities are close to making room for renewable energy sources, but the plants are closing faster than renewable energy and battery storage can keep up.

Wind and solar farms are among the most popular renewable energy sources, but their inability to generate electricity 24 hours a day means they must store part of their energy in batteries for later use.

However, while improved battery storage is being developed, operators are concerned that it will not be quick enough to replace the retiring reactors.

Supply chain concerns and inflation are limiting developers’ ability to procure the components required to create renewable energy farms, increasing the possibility of outages this summer.

The Electric Reliability Council of Texas’ interim chief executive, Brad Jones, told the Wall Street Journal, “Every market across the world is attempting to deal with the same challenge.” “We’re all trying to figure out how to make the most of our renewable resources while also ensuring that we have enough dispatchable production to maintain dependability.”

Others, on the other hand, have advocated for a more gradual phase-out of conventional plants.

“We need to make sure we have enough new resources in place and functioning before we let any of these retirements go,” Mark Rothleder, the California Independent System Operator’s chief operating officer, told the Wall Street Journal. “If we don’t, we’re putting ourselves at risk of having insufficient capacity.”