Air Conditioners Can Strengthen the Power Grid

Summer heat pushes millions to crank up air conditioning, but simultaneous AC use strains power systems. What if your cooling unit could do more than just cool? Recent research shows networks of home air conditioners can balance electricity supply and demand—acting like virtual power plants—to keep the grid stable without making you sweat.

Turning a Load into a Grid Asset

When temperatures spike, AC units everywhere kick in, creating a tidal wave of demand that can overload the grid and force operators to fire up costly, polluting generators. Those peaks not only drive up bills but also risk brownouts or blackouts on the hottest days.

The modern grid has grown more complex with the rise of distributed energy resources—solar panels, batteries, electric vehicles and smart devices—that can adjust their consumption on the fly. Yet storage on the grid remains limited, so every shift in demand must be met by flexible supply or smart load control.

A Field Test in Austin

From 2019 to 2023, University of Michigan researchers teamed with Pecan Street Inc., Los Alamos National Laboratory and UC Berkeley to connect 100 Austin homes’ forced-air AC systems to custom control boards. Homeowners agreed to have sensors and controllers installed, enabling two-way signals based on the grid’s frequency.

Every few seconds, the system nudged compressor on/off cycles up or down to follow frequency fluctuations around 60 hertz. In effect, the AC units responded like miniature power plants—drawing slightly more or less power to keep supply and demand in balance.

Results that Keep You Cool

The team ran four one-hour tests and found air conditioners matched grid performance of traditional generators. Even better, indoor temperatures never drifted more than 1.6°F from users’ set points, and override requests were nearly nonexistent.

• Rapid, second-scale frequency regulation
• Stable indoor comfort without manual overrides
• Enhanced grid reliability and easier renewable integration

Scaling Up with Smart Thermostats

This technology can plug into today’s internet-connected thermostats. Participating customers could earn bill credits by joining a utility or third-party service that fine-tunes AC load. Users stay comfortable and confident they’re strengthening the grid when it needs them most.

By transforming air conditioners into responsive grid assets, we open a direct path to smoother peaks, fewer emergency generators and greater uptake of renewable energy. The result is a cooler home, a cleaner grid and more reliable power on the hottest days.