Last January, the polar vortex brought extreme cold temperatures to much of the U.S., causing energy prices to spike as the natural gas system struggled and fossil-fuel power plants tripped offline.

In the aftermath, there was much hand-wringing about the growth of natural gas as a direct source of home heating, as well as its use for electricity generation. During a crisis, those two crucial needs can be at odds.

But now, new figures from the U.S. Energy Information Administration suggest that for the fastest-growing parts of the country, electricity is gaining share as the heating fuel choice. In the future, that electricity could increasingly come from renewable sources, such as wind or solar, that would not compete with natural gas.

Electricity as a heating fuel has gained market share in every region of the U.S. except for the Northeast, according to the EIA. In the Northeast, electricity for heat is growing, but it is mostly natural gas replacing oil. In the Midwest, natural gas and propane have lost market share to electricity since 2005.

Of course, the fastest-growing regions also tend to be those with the warmest climates. Electricity fuels more than 60 percent of homes in the South, and the West tracks closely with the national average of about 35 percent of homes using electricity.

The use of air-source heat pumps has largely driven the push for electricity in heating, as they have become about twice as efficient as those available 30 years ago. They are best suited to climates that don’t experience sub-zero temperatures for long periods of time.

For most homes, the primary choice of heating fuel also influences the fuel for other large energy needs, such as water heating and clothes drying. For regions where electric water heaters dominate, there could be an added benefit as renewable energy comes to account for a greater percentage of electricity generation: energy storage and grid balancing.