Every summer, millions of American households face the same quiet dilemma: turn up the air conditioning and brace for a painful electricity bill, or turn it down and endure the heat. It sounds like a small trade-off. For a growing number of families, it's anything but.
A new report from Duke University's Nicholas Institute for Energy, Environment & Sustainability, The Cost of Keeping Cool, puts hard numbers behind something we've been seeing on the ground for years: cooling a home in America is getting more expensive, faster than most people realize — and it's the households who can least afford it who are paying the highest price, in both dollars and health risk.
A Bill That Keeps Climbing
Nearly one in three US households now spends more than 6% of their income on home energy — the commonly used threshold for what researchers call "energy poverty." Nationally, the gap between what households can afford to pay and what they actually owe adds up to roughly $53 billion a year. Federal assistance programs like LIHEAP cover only a small fraction of that.
For a long time, this was mostly framed as a winter problem — heating bills in cold states. But the Duke researchers found something that should matter to anyone living in the Sun Belt: cooling costs are now rising just as sharply, and in some states even faster.
Between 2018 and 2024, the average cost of cooling a home rose meaningfully across states like Arizona, California, Texas, Florida, Nevada, Louisiana, and Mississippi. In parts of California, annual cooling costs climbed by as much as $100 or more in just a few years. And here's the part that surprised us most: the researchers found that most of that increase wasn't actually driven by rising temperatures. It came from something less obvious — climbing electricity prices. In some of the hardest-hit counties, electricity rate hikes accounted for close to 90% of the added cost, while hotter weather explained only a small slice of it.
In other words, even if the thermostat setting never changes, the bill keeps growing.
When Families Start Making Difficult Choices
The report's most sobering finding isn't about dollars — it's about what happens when families run out of room to absorb them.
According to the data, a meaningful share of US households now keep their homes at temperatures they themselves describe as unsafe, simply to avoid a bill they can't afford. Lower-income households run their air conditioning far less often than higher-income households — sometimes hours less per day during the hottest stretches of summer. And in parts of the Southwest, outdoor temperatures now regularly exceed the point where a fan alone can no longer keep a person safe from heat stress.
Meanwhile, the safety net hasn't caught up. Federal housing programs have historically treated heating as a baseline necessity but air conditioning as optional. Cooling assistance receives a fraction of the funding that heating assistance does, and most states still lack the kind of protections against summer utility disconnections that already exist for winter.
Put simply: the need for cooling is growing faster than our ability — individually and collectively — to pay for it.
Why This Matters Beyond the Electricity Bill
It's tempting to read a report like this and think of it purely as a policy story — something for lawmakers and utility regulators to sort out. But the underlying problem is a building science problem as much as it is an economic one.
Every degree that a roof absorbs from the sun becomes a degree an air conditioner has to fight against, and every extra hour an AC unit runs becomes a line item on a bill that, as this research shows, is only getting harder to justify. Homes with dark, heat-absorbing roofs work against their own cooling systems every single day of a heat wave — quietly driving up the exact costs this report describes.
This is precisely the problem cool roof technology was built to solve. By reflecting solar heat instead of absorbing it, a coated roof can lower surface temperatures dramatically and reduce how hard a cooling system has to work to keep a home livable. It doesn't touch electricity rates — that's a policy fight for another day — but it directly attacks the other half of the equation: how much cooling a home actually needs in the first place.
For homeowners in the very states this report flags as most exposed — Arizona, California, Texas, Florida, Nevada, and the broader Gulf Coast — that's not a marginal improvement. It's a meaningful buffer against a cost curve that's headed in one direction.
The Bigger Picture
None of this means cool roofs are a substitute for the policy changes this report calls for — better-funded cooling assistance, stronger summer disconnection protections, and utility allowances that finally treat air conditioning as the necessity it clearly is during a heat wave. Those changes matter, and they're overdue.
But while that policy conversation plays out, households don't get to pause their summers. The heat is here now, and so are the bills. Reducing how much cooling a home needs in the first place is one of the few things a family — or a builder, or a property owner — can control right away.
As extreme heat becomes a bigger part of American summers, the roof over our heads is quietly becoming one of the most important tools we have for keeping both our homes and our energy bills under control.
Source: Berg, E., P. Brimley, and A. Ward. 2026. The Cost of Keeping Cool: Energy Affordability and Extreme Heat. Nicholas Institute for Energy, Environment & Sustainability, Duke University.