Great Lakes Taps Waste Heat as New Clean Energy Source

Imagine if two-thirds of the energy from a massive nuclear power plant just disappeared into a lake as waste heat. That's exactly what's happening at Ontario's Pickering Nuclear Station, and it's just one example of the stunning energy waste across the Great Lakes.

But a quiet revolution is underway to capture all that lost heat and put it to work warming homes and businesses. The technology isn't new or experimental. It's been proven for over a century, and northern Europe has already embraced it on a massive scale.

Here's how it works: Power plants dump excess heat into cooling water. Data centers convert nearly all their electricity into heat while running our Zoom calls and internet searches. Even the sewage flowing beneath city streets maintains a steady 60 degrees year-round, carrying thermal energy that currently goes nowhere.

Cities across the Great Lakes are now tapping these heat sources through district heating systems. These work like giant radiators, circulating hot water or steam to multiple buildings at once. St. Paul, Chicago, Rochester, and Lansing already use district heating downtown, while Toronto cools 80 buildings using deep lake water.

Paul Kohl leads the Sewer Thermal Energy Network, a group advocating for one of the most overlooked heat sources. Building owners can install heat pumps that pull warmth from sewer lines running beneath their properties. The sewage stays safely contained in pipes while transferring its heat, and the system uses far less electricity than traditional heating.

The timing couldn't be better. Many building owners want to stop burning fossil fuels but can't get enough electricity from strained power grids. Water-based heat pumps solve both problems at once.

Luke Gaalswyk runs Ever-Green Energy in St. Paul and sees enormous potential. His company is exploring wastewater as a heat source because the engineering is already proven. The real barriers aren't technical but political and financial. Unlike Europe, the United States lacks strong policy frameworks and funding mechanisms to incentivize waste heat recovery.

The Ripple Effect

The benefits extend far beyond lower heating bills. Capturing waste heat means fewer carbon emissions from buildings, less land disruption for new power plants, and reduced thermal pollution flowing into lakes and rivers. It also shields communities from volatile fossil fuel prices while meeting growing electricity demand from data centers and electric vehicles.

The Great Lakes region sits on an abundance of wasted energy that could power cleaner, cheaper heating for decades to come. Cities that act now will build resilience while helping preserve the precious water resources that define the region. Northern Europe has already shown the path forward.

The challenge isn't figuring out if waste heat recovery works but building the awareness and political will to make it a priority across the region.