Those figures are certain to change as the weather warms and if the lockdowns continue, or if some restrictions are lifted and more businesses reopen.

The Columbia researchers noted that there is little demand for cooling in April and consequently little stress on the power distribution grid. But in warmer months, as more stuck-at-home apartment dwellers run air-conditioners longer, energy use will climb even more. “If you extrapolate to May, June, July, that could get you into territory where you won’t be able to say anymore, well the grid, no problem,” Dr. Meinrenken said.

“The challenge of this stuff is it could occur, but locally,” potentially straining transformers and other equipment in areas that are mostly residential, said Vijay Modi, a professor of mechanical engineering at Columbia who is involved in the study. “A weekday peak is what the utility has to worry about.”

Anne Marie Cobalis, a spokeswoman for Con Edison, the utility that supplies power to the city, said crews were working to harden the grid for peak summer demand, replacing and upgrading transformers, cables and other infrastructure.

“If things stay as they are into the summer months, we anticipate seeing a rise in residential usage and some additional commercial usage for air conditioning,” she said. Should any part of the grid become stressed, she added, the utility is ready to provide temporary equipment like mobile generators.

Nationally, reduced overall demand should continue into the summer even if more of the economy reopens, said Adam Jordan, an analyst with Genscape, which provides pricing and other forecasts to the electricity industry. The reduction in demand makes it unlikely that broader grid reliability problems will appear this summer even if residential consumption rises, Mr. Jordan said. “In terms of keeping the lights on, this isn’t really a big threat.”