The ocean could be a boundless source of cheap energy, if only we could figure out how to tap it. A British startup has just announced an intriguing new idea: A long fence of shallow water turbines that would soak up the power of tides as they roll toward the beach.
According to Kepler Energy, these tidal fences can produce more juice more cheaply than off-shore wind farms. Kepler’s “Transverse Horizontal Axis Water Turbine” consists of a string of linked carbon composite turbines, placed at the best spots beneath the ocean’s surface to exploit tidal flow. Its modular design ensures that each turbine can start generating electricity as soon as it’s installed; however, the power coefficient of the entire fence is proportional to its length. That’s a fancy way of saying that over the long term, bigger fences give you a lot more bang for your buck.
Conceptual model of Kepler’s tidal energy fence, via Kepler Energy
Kepler hopes its tidal fence will prove friendlier to marine life than previous offshore wind or ocean power installations. The fence is designed to be placed in relatively shallow, slow moving water, which in theory means there’s less danger of its turbines becoming the world’s largest open-water fish blenders. (The company has yet to undergo the environmental impact assessments needed to support that claim.)
As a proof of concept, Kepler recently announced its intentions to raise £142.6 million USD to install a one kilometre fence in the Bristol Channel. The fence’s total output will be roughly 30 MW, enough to supply power to 1,000 homes. This may sound like a pretty pricey science project, but Kepler chairman Peter Dixon is taking the long view: “If we can build up to, say, 10km worth, which is a very extended fence, you’re looking at power outputs of five or six hundred megawatts,” he told Reuters. “And just to visualise that, it’s like one small nuclear reactor’s worth of electricity being generated from the tides in the Bristol Channel.”
Ocean energy concepts come and go like memes these days, so we should take this one with a big grain of salt until it’s actually installed. Still, it’s a clever idea, and given the desperate need for solutions to our fossil fuel dependency, I’m going to light a candle for Kepler.
Top image: Render showing how a tidal energy fence will look installed, via Kepler Energy