On 22 January 2009 the Scottish Government signed off on what was supposed to become one of the world's most ambitious wave-power schemes. A breakwater of ten concrete caissons would sit on the seabed four hundred meters off Siadar Bay on the north coast of Lewis. Inside the caissons, thirty-six to forty Wells turbines would spin in air pushed and pulled by the rise and fall of the Atlantic. The estimated cost was thirty million pounds. The estimated capacity was four megawatts. Headlines called it green-for-go. Three and a half years later it was cancelled, the seabed at Siadar still unbuilt-on, the turbines never installed.
Siadar Bay opens to the northwest, a shallow scoop in the Atlantic-facing coast of Lewis where swell from a thousand miles of open ocean piles up against the shore. That energy is what made the bay attractive to engineers. The plan, developed by Inverness-based Wavegen with backing from npower Renewables, was straightforward in concept and demanding in execution. A two-hundred-meter causeway would link the breakwater to the mainland for access and grid connection. The caissons, hollow concrete chambers, would house oscillating water columns: as a wave entered the chamber, the rising water pushed air through a turbine; as the wave retreated, air rushed back the other way. Wells turbines are designed to spin in the same direction regardless of which way the air moves, which is what made the technology suited to the relentless two-way breath of the sea.
Lewis sits on one of the best wave-energy resources in Europe. The Outer Hebrides catch swell that has been building across the entire North Atlantic, and the consistency of that energy is precisely what an intermittent renewable like wind cannot offer. The Scottish Government had been backing marine-energy schemes for years by the time Siadar received consent, partly to meet climate commitments and partly because remote islands like Lewis had the resource on their doorstep and the grid constraints that made local generation valuable. If Siadar had worked at scale, it could have demonstrated that an island community could build, host, and benefit from a piece of energy infrastructure entirely new to the world.
The trouble was money, and time, and the slow grind of getting any first-of-kind engineering project across the line. In August 2011 npower Renewables, by then taken over by the German utility RWE, withdrew. The official explanation was commercial: the project no longer fit the company's investment criteria. Wavegen carried on alone for a while, but in December 2012 the scheme was cancelled outright. Marine-energy companies up and down the Scottish coast were facing the same headwinds. Aquamarine Power, Pelamis Wave Power, and others followed similar trajectories over the next several years, ambitious projects in turn approved, partially funded, and finally shelved as costs proved stubborn and grid arrangements remained difficult. The bay at Siadar today carries no trace of what was almost built there.
Standing on the cliffs above Siadar, watching whitecaps roll in from the open ocean, the energy is obvious. Capturing it is not. The same wildness that makes Hebridean swell so promising to engineers also makes it brutal on equipment, expensive to install, difficult to maintain, and unforgiving of mistakes. Siadar belongs to a long Scottish lineage of marine-energy ambition that has yet to find a commercially repeatable design. The next attempt, when it comes, will know more about what defeats wave power than the engineers of 2009 did. The bay will be waiting. So will the Atlantic.
Siadar Bay lies at 58.34 degrees north, 6.79 degrees west, on the north coast of Lewis. From the air the bay is a shallow notch in the cliff-edged Atlantic shoreline; the wave farm would have sat about four hundred meters offshore from the village of Siadar Iarach. Stornoway Airport (EGPO) is roughly 18 miles southeast. The Butt of Lewis lighthouse, the northernmost point of the island, lies about 12 miles northeast. Flying west to east along the coast at low cruise gives the best view of how exposed this shore really is, with no shelter between Siadar and Labrador across the open ocean.