America's answer to hotter summers has overwhelmingly been more air conditioning, and engineers are now looking for ways to keep people cool without driving up electricity demand.

Why it matters: The need for cooling is surging. The issue isn't just how to generate more electricity — it's how to use less of it and ease demand when grids are most strained.

Between the lines: A July study finds that keeping buildings cool without relying solely on AC will be critical for adapting to climate change.

  • AC is already nearly ubiquitous in the U.S., but that doesn't mean its electricity consumption has peaked.
  • "The market is saturated, but the use of air conditioning or the energy consumption for air conditioning will increase because of the overheating," Mat Santamouris, a University of New South Wales professor and the study's lead author, tells Axios.
  • Higher temperatures mean Americans will run AC more, while cooling is becoming increasingly necessary in northern parts of the country that historically needed less of it.

Threat level: More AC means more electricity demand at the very moments the grid is under the most pressure.

  • AC can account for roughly half of total peak electricity demand on the hottest days in Texas, according to an International Energy Agency analysis.
  • Ankit Kalanki, lead cooling expert at clean-energy nonprofit RMI, tells Axios that "saving 1 kilowatt-hour of energy at midnight is not the same as reducing 1 kilowatt of peak demand at 6 p.m. when everyone is coming back from the office and turning on the air conditioner."

The big picture: Meeting America's growing need for cooling doesn't have to mean supplying all of it with more electricity.

  • "We really have to avoid the solar radiation [entering] the building," Santamouris says. Letting that heat in and then spending electricity to remove it, he adds, "is not so intelligent."

State of play: The options largely fall into three categories: Keep heat out, cool more efficiently and ease demand on the grid.

  • That includes smart windows and shading to block heat, reflective roof coatings, built-in energy storage to ease peak demand, and automation and ventilation to cut down on AC use.
  • In Colorado, RMI and Boulder County are testing passive daytime radiative cooling paint on roofs. Kalanki calls it "a more advanced version" of white paint: It reflects sunlight while also radiating heat into the sky.
  • Blue Frontier's air conditioners use a liquid desiccant to remove moisture from the air and built-in energy storage to reduce power use during peak-demand hours.

Yes, but: There's no single cooling equivalent of double-pane windows.

  • The right mix of cooling technologies depends on climate, building type and location, Santamouris says.

Case in point: A 2024 study co-authored by Santamouris modeled heat-mitigation strategies in Riyadh, Saudi Arabia, and found that combining cool materials and greenery could reduce peak ambient temperatures by up to 4.5°C.

Reality check: None of these technologies eliminates the need for AC, which can save lives during extreme heat. The goal is to reduce how frequently and intensely it operates.

The bottom line: "Efficiency is the cheapest resource that we have available," Kalanki says, because reducing demand can avoid the need for new generation, transmission and distribution infrastructure.

Go deeper: The U.S. just had its hottest month on record