Submersible hydroelectric technology deployed across the Great Lakes could become a key cog in clean energy efforts, supporters say, amid surging electricity demand and costs.

Home to one of the largest deposits of freshwater on the planet, the Great Lakes region has on its shores some of the largest cities in North America in Chicago, Toronto, Montreal and Detroit, where electricity demand is growing. While none of the five Great Lakes have significant tides or currents to fuel hydropower, several of the waterways that link the lakes do.

Last month the Ocean Renewable Power Company (ORPC), an entity that has operated submersible hydroelectric projects in Alaska and Maine for years, announced its first urban venture on the St Lawrence River in Montreal, which is set to begin operating two hydroelectricity devices later this year.

“The St Lawrence River is one of the best opportunities in North America for our technology because it has consistent, high-velocity water for hundreds of miles. In the Montreal area, there’s 60-90 megawatts of resource potential alone,” says ORPC chief executive officer, Stuart Davies.

“The Niagara River, the St Lawrence River are big powerful rivers driven by the hydrology of the lakes draining out.”

The devices use turbines made from carbon fiber that look like the blades of an old-school push lawnmower and are turned by the flow of water.

Current- and tidal-powered hydroelectric generators have been growing in popularity and efficiency across the world. In Scotland, the world’s most powerful tidal hydro generator can power up to 2,000 homes. In Korea, the Sihwa Lake tidal power station generates about 550GW of electricity, the equivalent of 862,000 barrels of oil.

But now North America is catching up.

Orbital Marine Power, the company running the Scotland project, announced in November that it plans to deploy up to three O2-X tidal devices in the Bay of Fundy’s Minas Passage in Nova Scotia.

ORPC is expected to begin a second Great Lakes project on a section of the Niagara River in Buffalo, New York, later this year.

The rise in marine power generation is happening at a time when, across the Great Lakes, electricity prices for residential and industrial consumers have surged.

Last September, the New York public service commission approved rate and delivery charge increases that saw residents of western New York, including Buffalo, hit with significant electricity bill hikes. More rate increases are scheduled for later this year and in 2027.

Similar stories are playing out for millions of people in Michigan and Ohio, where divisions between public administrators and communities brought about by datacenters are fueling major fissures in rural America.

Davies says that while the enormous electrical demands of large data storage centers are far greater than the half a megawatt to five megawatts ORPC’s devices can generate, there are business applications for its technology.

“If you’re an industrial customer and you’re thinking about the growth of AI … We can be that 24/7 electricity resource that’s part of a baseload in normal times and if the grid goes down for some reason, that river still runs,” he says.

“You’re going to have that level of emergency power.”

But these efforts are not without challenges and controversy.

While administrative authorities in Montreal and Quebec already have a longstanding culture of deploying hydropower that results in low-cost electricity for customers, Great Lakes cities and states in the US do not. In the US, it takes an average of eight years for a hydroelectricity facility to become fully licensed.

The presence of spinning turbines in waterways that are home to dozens of fish species and other wildlife has drawn concern from some environmentalists.

“With regard to hydrokinetic energy in general, we are not opposed to it at all. Responsible, sustainable energy sources need to be encouraged,” says Anne KC McCooey of the Black Rock Riverside Alliance in Buffalo.

“However, the key word is responsible. You can’t put something up just for the sake of harnessing the energy, while at the same time doing harm [or potentially doing harm] to the environment and the human and non-human life that depend on that environment.”

ORPC says that at a site in Alaska where its turbines have been deployed since 2019 to provide electricity for a small community, there has been no record of fish injuries caused by the devices on a waterway through which tens of millions of grown and juvenile sockeye salmon migrate each year.

Moreover, other environmental factors play a significant role in deciding where this technology is suitable. While the St Lawrence and Niagara rivers are fast-flowing waterways situated toward the end of the Great Lakes watershed, the rivers and straits linking lakes upstream are largely slow-moving.

But scientists are working to bridge that gap.

Where Lake Huron flows into the St Clair River 50 miles (80km) north of Detroit, Michael Bernitsas, a professor at the University of Michigan, has tested a hydroelectricity generating technology called Vivace that can harness hydro energy from water that moves as slow as half a meter per second.

“The current there gets to about 2.3 to 2.5 knots, which is pretty slow for turbine technologies. But it’s very easy for Vivace to harness that power,” he says.

As water moves, it pushes cylinders which oscillate up and down on the device, generating kinetic energy. Bernitsas says the devices can be manufactured in sizes starting from under a meter in width and height to a scale suitable for larger projects.

“The immediate market for our small technology would be portable applications in situ in the ocean, for example powering Noaa buoys,” he says.

He estimates it would take up to two years, depending on funding, to get the devices to a point where they are available to be sold commercially.

A significant advantage to operating in Great Lakes water is the absence of salt, meaning that corrosion, an issue that can trouble ocean-based projects, is not a concern and allows materials to last far longer and thus reduces the overall cost.

Some tidal projects, particularly those operating in northern Europe, can be anchored to the bed of a river or lake, eliminating problems that may arise due to surface ice in winter. ORPC, whose Alaska project saves the village of Igiugig the equivalent of almost 23,000 gallons of diesel or 414 metric tons of carbon dioxide annually, is also planning on going down that route.

Davies say the company is in the planning stage of a project on the lower Mississippi River, potentially between Baton Rouge and New Orleans, for late next year.

“The biggest [challenge] is just the lack of awareness of our solution, but that’s really flipped in the last nine months. We still keep our 40-50% tax credit, while wind and solar [equivalents] are sunsetting,” says Davies, referring to the Trump administration eliminating Biden-era federal subsidies for solar and wind energy ventures. According to the National Hydropower Association, investment and production tax credits for marine energy in the US will remain in place until at least 2033.

“All of a sudden, our relative competitiveness has changed dramatically. We’ve had a lot more interest. Entities from over 70 countries have reached out to inquire about the technology.”