By Peter Voskamp
States along America’s roughly 100,000 miles of coastline consume about three-quarters of our nation’s electricity. But how much of that energy comes from the vast pool of potential electricity lapping at the shoreline next door to tens of millions of Americans via tidal power?
Barely a drop.
A group of small, U.S.-based tidal energy startups, including several in New England, are seeking to change that dynamic.
While all forms of energy generation – including tidal energy and other renewables – have environmental impacts and require appropriate siting and through environmental review, marine hydrokinetics, as tidal and river energy are also known, offer reliable, largely predictable sources of renewable energy.
Every day there are two high tides and two low tides. But the challenge is how, exactly, to extract kinetic energy from this moving water – be it from ocean tides or river currents – in an economically viable way.
There are currently about a dozen U.S. companies in the nascent industry. Less than half of those have actually deployed equipment in the water.
Portland, Maine-based Ocean Renewable Power Company was one of the first U.S. companies to dip its toe in the water. Founded in 2004, ORPC is the first company in the world to deploy marine hydrokinetic systems in both ocean and river environments and send power to shore.
Turbine Generator Unit
ORPC has spent the last eight years improving its turbine generator unit, or TGU. These devices vary in size depending on where they will be deployed. The ocean TGU is roughly 100-feet long and 18-feet high, generating electricity via four large spinning turbines attached to a drive shaft. The river version is significantly smaller.
The first TGU prototype was tested in 2007, and five years later ORPC deployed its first grid-connected system in Cobscook Bay, by Eastport and Lubec, Maine, which opens into the Bay of Fundy. This 150-kilowatt system was the first ocean-based clean energy project not using a dam deployed anywhere in the Americas. The pilot project operated for a year, and it received support from the U.S. Department of Energy, according to CEO Chris Sauer.
The Bay of Fundy has the best tidal resources in the world. About 100 billion tons of seawater pass in and out of the bay each day, more than the combined flow of all the world’s freshwater rivers.
The company has entered into a 20-year power purchase agreement with the utility company Emera Maine for its Maine Tidal Energy Project, which includes its successful Cobscook Bay pilot project. ORPC’s Maine Tidal Energy Project will see the company expand its deployments to create a commercial system with a capacity of up to 5 megawatts. Construction is anticipated to start in 2017.
Depending on the conditions there could be up to 20 TGUs deployed in the project. Under optimal tidal current conditions, an individual TGU can generate up to 600 kilowatts of electricity. The specific resources and current speed at each site will ultimately determine the number of TGUs installed and their individual outputs.
The Maine Tidal Energy Project is selling electricity at an above-market rate, approved by the Maine Public Utilities Commission (MPUC), which supported the project as an investment in the clean energy economy of Maine. According to the MPUC, the project benefits of jobs and related economic impact are expected to be worth nearly twice the cost of the above market rate over the lifetime of the long-term PPA.
ORPC itself employs 18 people. The Maine Tidal Energy Project is expected to directly create 43 jobs in Maine beginning in 2016, resulting in approximately $2.5 million in payroll.
North to Alaska
If the Bay of Fundy harbors more potential than anywhere else in the world for deploying commercially viable tidal energy, the next-best location in the Americas is Cook Inlet, Alaska, near Anchorage.
Here, ORPC is working with the Homer Electric Association, a rural electric co-op, to establish a pilot project near Nikiski, a town of about 4,500 located on the Kenai Peninsula south of Anchorage. Eventually, ORPC hopes to install a 5MW commercial installation near this site.
Sauer, the CEO, said it’s “islanded communities” like Igiugig, Alaska, 275 miles southwest of Anchorage and accessible only by boat or plane, that are the company’s target market.
Approximately 700 million people worldwide live in remote areas that rely upon diesel-powered microgrids, which can drive electric prices as much 15 times above market rate. While some islanded Alaska communities like Kodiak have turned to wind energy, other locations may in the future find tidal energy to be the more economical option.
However, as it stands the domestic tidal industry “can’t compete with the grid,” Sauer said.
Sauer said that if the marine hydrokinetics industry were to receive tax incentives similar to the solar and wind industries, the industry could stand on its own in 10 years, offering prices “compatible with the grid.”
Currently, tidal energy receives about half the federal tax credits the wind and solar industries receive. Sauer would like to see more tax incentives up front for accelerated depreciation and private investment. He said the Energy Department has been “a lifeline for us,” and he hopes the agency will continue to be adequately funded.
It costs ORPC between $7,000 and $8,000 per kilowatt to operate their TGUs. Sauer expects that will be cut in half by 2017.
As a “start-up company in a start-up industry,” Sauer said ORPC is dealing with “risk, squared.”
Reach Peter Voskamp at email@example.com.