The non-profit Marine Renewable Energy Collaborative recently announced plans to build a tidal energy test site in Cape Cod Canal, the first of its kind in the United States. The hope is to catalyze the development of a new generation of smaller, more efficient tidal energy devices that could benefit coastal and island towns around the globe.
The man at the helm is John Miller, executive director of the Marine Renewable Energy Collaborative and, before that, of the now defunct Marine Renewable Energy Center at U Mass Dartmouth. In both cases, small-scale tidal energy generation has been a major focus.
That’s in distinct contrast to the rest of the tidal energy industry. Conventional wisdom holds that, to make tidal energy feasible, big tides are needed to get enough water flowing fast enough to push big turbines. As a result, commercial developers have focused on places like northern Scotland and Canada’s Bay of Fundy, where the difference between high and low tide can be more than fifty feet.
Miller argues that there’s a fundamental flaw with this approach. He likens putting the first tidal turbines in the path of extreme tides to putting the first large wind turbines on Mt. Washington. What’s more, he says that the exclusive emphasis on big tidal misses another, wider potential market – small off-grid, or end-of-the-line, communities.
“There are a lot of places in the world where you have rivers or small estuaries that you could put in smaller turbines and be competing against diesel generators at fifty or sixty cents a kilowatt,” says Miller. “The problem is that those are smaller, one-of-a-kind sales opportunities, so they’re harder to do than the large scale utility.”
What’s more, Miller says new, more efficient technologies are needed to really capitalize on slower flow rates, and better withstand ocean conditions. In particular, he envisions tidal devices with flaps or fins, based on the bodies of ocean animals, rather than birds.
“I like to think of evolution as being a few hundred millions years of product development,” quips Miller. “Wind turbines were designed to take advantage of things that were discovered in the development of airplane wings, which come from bird wings. But you don’t see a lot of bird wings in the ocean.”
While Miller says ocean-adapted technologies are coming out of universities, up to seventy percent of research funding can be eaten up by permitting, alone.
The Bourne Tidal Test Site is Miller’s answer to those challenges. The Marine Renewable Energy Collaborative has gotten funding from Massachusetts Seaport Economic Council to build a platform in the west end of the Cape Cod Canal that would hold turbines up to three meters, or about ten feet, in diameter. The platform will be close enough to shore to allow devices to be installed by crane (far more cost-effective than hiring a ship), and it will be connected to a battery and electrical system at a nearby parking lot. The idea is to give technology developers a place to test full-scale devices in real-world conditions at a relatively modest cost.