The Energy Department says the government should make it easier and cheaper to operate power plants, including coal and nuclear plants, to strengthen the nation’s electric grid.

The department said in a report Wednesday night that the closure of many plants that once formed the backbone of the grid has raised the risk that consumers might not have reliable electricity.

In a letter accompanying the report, Energy Secretary Rick Perry says the U.S. is fortunate to have many sources of energy and should use them all.

Advocates for renewable energy have been bracing for the report since drafts that leaked to the press in recent weeks hinted that the Energy Department would conclude that renewable energy and federal regulations have done little to improve grid reliability.