U.S. Start-up Harnesses Tidal Power

With interest in solar and wind power waning, can Ocean Renewable Power Company make tidal energy the next big thing?
ORPC's TidGen turbine generator, shown here, was lowered into Cobscook Bay off the coast of Lubec, Maine, on Tuesday, August 14.

The ocean covers two-thirds of the planet. One young company is asking: Why shouldn't the ocean power the planet? 

Based in Portland, Maine, Ocean Renewable Power Company, is betting on tidal power. And it has developed a massive, 80,000-pound underwater turbine that will, for the first time in the United States, harness the ocean's tide to generate electricity for the power grid.

Last week, the behemoth turbine was lowered into Cobscook Bay, just off the coast of Lubec, Maine, and is expected to begin generating power by September. It's the beginning of a new type of power generation, which the Department of Energy estimates could constitute 15 percent of the country's electricity by 2030.

Chris Sauer, ORPC's co-founder and CEO, takes it a step further: "We think this will ultimately prove to be the most environmentally benign method of generating electricity yet."

The way TidGen, as the turbine is called, works is remarkably simple. Stretching 98 feet long by 17 feet wide, it's made up of four rotating turbines, at the center of which is a rotating generator. As the tide lifts and spins the turbines, they spin the generator, activating magnets within the generator to create energy. The turbine's bearings are water-lubricated, so there's no grease or oil required. It moves, in many ways, exactly like an old-fashioned paddle wheel, which begs the question: What took this so long?

"It may look simple, but if you peel back the layers, there's a lot of complicated technology in there," Sauer says.

In fact, according to Sauer, some of the materials required to build TideGen weren't even fully developed when ORPC co-founder Captain Paul Wells first conceived of the turbine in 2004. Having spent most of his adult life working in the cruise ship industry, Wells had been contemplating the connection between the ocean's tide and energy for years. The problem was, he had no energy-sector experience.

"He knew a ton about tidal currents," Sauer says, "but very little about electric currents."

So he attended the International EnergyOcean Conference in 2004 to find out more. It was a speaker there who eventually led Wells to Sauer and ORPC's third co-founder, John Cooper. Both are power industry veterans, who initially agreed to join the project as consultants.

But, Sauer says, "We got hooked on this idea of trying to get energy from the ocean. I thought it was a long shot, but if you could actually do it, it could really be something."

They stopped referring to themselves as consultants, and instead, formed a company with Wells in September of that year. It took two and a half years just to design the turbine on paper, working with the U.S. Navy to conceive of material that would be both lightweight and durable. Once they found that material, they had to carefully design the turbine's foils to be wide enough to catch the tide on the way up, but angled in such a way that they wouldn't catch water on their way back down. According to Sauer, this maximizes "lift" and minimizes "drag," which is what makes the TideGen vastly more efficient than other hydrokinetic technology. That efficiency is what Sauer hopes will allow ORPC to grow to commercial scale.

So far, that plan is going well. The company has already negotiated a 20-year power purchase agreement with the Maine Public Utilities Commission. Though the first turbine will only generate enough energy to power about 25 homes, ORPC is contracted to install another 20 devices by 2016, including two that will be installed next year.

Ultimately, Sauer says, the project will generate enough energy to power 1,500 homes. Based on the output of each turbine, Sauer estimates the project will eventually generate several million dollars a year.

He sees other possible revenue streams as well. ORPC could also sell off renewable energy credits and provide technical services and site assessments to other towns that are interested in tidal energy.

"We all believe this is a good thing," Sauer says, "but we also all believe we can make some money on this, too."

Still, ORPC has plenty more hurdles to climb before then. For starters, there's competition on the horizon. Although TidGen is the first operational turbine licensed by the Federal Energy Regulatory Commission, another company called Verdant Power, which also received a license this year, will reportedly begin installing turbines in New York's East River in 2013.

Meanwhile, in countries such as Scotland and Ireland, which have particularly strong ocean currents, tidal power has been available for years. As the industry matures overseas, some municipalities are looking to import their turbines. Already, Washington's Snohomish County Public Utility District is sourcing its turbines from an Irish company called OpenHydro.

"We think eventually they'll want to use ours," Sauer says.

There are the environmental considerations, as well. According to Sauer, the turbines have yet to have a negative impact on sea life, but ORPC will continue to monitor (and face questions about) their affects, as well as their influence on the tide itself. Technically, Sauer says, if enough of these turbines were scattered around the world's oceans, it could stop the flow of the tide in crucial places like the Gulf Stream.

"Northern Europe would go through another Ice Age, because the Gulf Stream flowing around it is what keeps places like the coasts of Britain and France from freezing," he says. "It's something to be studied over time, but we know over the next 20 years, at the rate we're growing, it won't be an issue."

Bringing down costs is also a major concern for Sauer. ORPC landed $21 million in funding for the first three turbines, $10 million of which was from the Department of Energy. Funding for the remaining 17 turbines will come largely from the private sector, meaning it will be important for Sauer to demonstrate high profit margins.

"That's what happened in the solar and wind industries. To stay competitive, they had to increase efficiency and reduce costs," Sauer says. "That's the grind we're on now."

IMAGE: Photo courtesy of ORPC
Last updated: Aug 22, 2012

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