The Tide Is Turning for a New Source of Green Energy
The U.S. Energy Department estimates tidal streams in the U.S. could generate enough electricity to power nearly 30 million homes a year.
The industry, though, is still in its infancy. Some projects in the works include French company OpenHydro, which says it is close to linking two tidal machines off Brittany to create a 1-megawatt tidal array. U.K.-based Tidal Lagoon Power has proposed to build a tidal turbine system called the Swansea Bay project that would generate 320 megawatts.
In the U.S., companies in Oregon, Washington, and Maine are in various states of trial and testing of tidal power systems. This week, the federal government selected 10 organizations to share more than $20 million in funding to be used to explore ways to generate electricity from ocean waves and tidal currents.
The ocean’s constant motion is a boon to steady power production but a bane for engineers, who must develop a cost-effective generator capable of withstanding the relentless pounding and corrosive marine environment.
On the Shetland Islands, residents are weighing the environmental impacts that would come with a beefed-up tidal array system against the potential impacts of a planned wind farm. One group, known as Sustainable Shetland, has been fiercely opposed to a proposed 103-turbine, 307-megawatt wind farm that’s been in the works since 2008.
Frank Hay, chairman of Sustainable Shetland, said the project would replace environmentally important peatlands, and many of the turbines would be placed within 1.5 miles of residences.
“We recognize that renewables must play a part in how we live in the future. However, these schemes must be fit for scale and fit for purpose,” Hay said. “A wind farm of this scale is wrong for Shetland.”
“A major problem for tidal energy is that to make it large-scale it will require a large area of seabed, and this could have issues for fishermen as well as marine life in the area,” Hay said. “It would appear that nearly every renewable system would have some negative aspect.”
Government officials have already designated two regions south of Shetland—Pentland Firth and Orkney Waters—as Marine Energy Parks, aimed at streamlining the commercial-scale leasing process to get potential prototypes and projects online faster.
Those locations, Lang said, “offer further opportunity for Scotland’s marine renewable businesses to develop wave and tidal devices. We’re already at the forefront of these important technologies, and energy park status will help speed up the commercial development of marine renewable devices.”