Marine energy fans have something new to buzz about this week, now that the US Department of Energy has dropped another round of $10.5 million in funding for next-generation technology to tap river currents as well as ocean currents, waves, and tides. The new funding is aimed at lowering the cost of the nation’s vast marine energy potential by building up durability and ease of maintenance, as well as increasing efficiency.
Marine Energy: The Water Mills Of The Future
The technology to tap rivers for power goes back to the earliest water mills, and that’s the basic idea behind marine and hydrokinetic energy systems. All of these rely on the natural motion of water rather than the high pressure infrastructure required by hydroelectric dams.
While ocean-going devices have been grabbing much of the marine energy spotlight these days, the US also has an abundance of potential interior sources that could be tapped, including rivers as well as existing dams and other built infrastructure such as irrigation canals, water treatment plants, food processors, and other facilities that use large amounts of water.
This wide range of deployment dovetails with the distributed power generation strategy that the Energy Department has been pursuing under the Obama Administration. Here’s the rundown on a river-based hydrokinetic demonstration project now under way that pairs the agency with the company Ocean Renewable Power Company (ORPC):
In July 2015, ORPC deployed its RivGen® turbine in the Kvichak River, located at the Igiugig village in Alaska. The RivGen® Power System demonstration project is providing power to Igiugig, displacing power that would otherwise be generated by high-cost diesel fuel. Connecting to the small community grid and decreasing the use of diesel fuel will help lower electricity costs for consumers since all fuel must either be barged or flown in to the rural village, and that cost is passed on to rate payers.
And here’s the hydrokinetic system in action:
Big Bucks For Marine Energy
With all that in mind, let’s take a look at the new round of $10.5 million for advanced marine energy systems.
The funding is divided into two groups of three. The first group focuses on ocean energy, aimed at improving the durability of wave energy converters (WECs).
Part of the funding will go to California-based Dehlsen Associates, to improve upon its multiple-pod design.
M3 Wave LLC of Oregon will also share in the pie. As the developer of an underwater WEC that harvests energy from ocean swells, it will tackle the challenges posed by shifting sediment that could displace the device. The company will also work on improving the design to reduce maintenance costs.
Another company in this group, Oscilla Power, Inc. of Washington, will work on storm-related survivability challenges faced by WECs that float on the surface.
The other three projects are aimed at improving installation, operations, and maintenance for marine energy devices:
Columbia Power Technologies, Inc., of Charlottesville, Virginia, will develop and deploy a streamlined, cost-effective installation and recovery process that includes design updates and process improvements related to IO&M, while deploying the floating, offshore WEC.
Igiugig Village Council, in southwestern Alaska, will develop a river turbine system that will demonstrate IO&M design improvements to simplify maintenance and make system components more durable during operations.
Verdant Power, Inc., of New York, New York, will complete their TriFrame foundation, which optimizes turbine spacing and support structures to allow for cost-effective IO&M.
Marine Energy For NYC
If Verdant Power rings a bell, you’re probably thinking of the company that’s developing a major marine energy system in the East River, deep in the heart of New York City between Manhattan and Brooklyn. The turbines, shown here under construction on land, resemble stumpy wind turbines:
The East River is actually a tidal strait and not a “real” river, so on the plus side its current is more consistent than an inland river, as explained by Verdant Power:
…when the water velocity exceeds approximately 1.0 m/s (3.3 ft/s, 2 knots), the turbine blades begin to rotate and the units generate electricity for about 4 hours (red areas in figure). As the tide shifts direction, the turbines yaw (turn ~170 degrees) to generate power from the current flowing in the opposite direction. This cycle repeats in a very predictable manner approximately every 6 hours. The regular nature of tidal currents provides a significant advantage for tidal power as compared to other energy systems.
Verdant has been steadily hammering away at the East River project since 2002, and it passed a major milestone in 2012, when it received a federal permit to operate. News out of the company has been rather quiet since then, but with a share of that $10.5 million in hand it looks like Verdant is gearing up for another milestone.
Images: top (screenshot) via US Department of Energy, middle (cropped) via ORPC, bottom (screenshot) via Verdant Power.
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