After losing the wind wars to the Danes in the early ‘80s, Scotland is on the verge of owning a small, yet significant new power market – tidal energy.
Inventors have long dreamt of harnessing energy from the daily ebb and flow of ocean tides using underwater windmills. Yet a large-scale tidal farm has remained elusive – at least, until now. Making use of Scotland's geographic assets and answering a renewed call for an energy alternative, Aberdeen scientist Ian Bryden is putting his new invention, “the Snail,” to work.
Widely known among scientists as the godfather of tidal power, Mr. Bryden is capitalizing on his country's home field advantages, namely a northern latitude location with severe tidal changes and fast-moving channels. Recent technology improvements, like anti-corrosive coatings and highly efficient turbines, are aiding the efforts.
The government is strongly supportive. Facing diminishing gas supplies, the country is eager for energy alternatives. Ofgem, Scotland's energy regulator, has issued a stark warning: it may not have enough power to get the country through a winter within the next three years. Such a shortfall would force an increase in gas imports, and an unwelcome reliance on neighboring countries. The government has big plans for tidal power, aiming to build several large farms by 2010 for generating electricity.
As incentive – and enforcement – Scotland’s government instated the Renewable Obligations initiative in 2002, passed as part of the 2000 Utilities Act. It requires 18 percent of power suppliers’ energy to come from renewable sources by 2010, and 40 percent by 2020. Renewable Obligation Certificates (ROCs) serve as cash incentives, granted to those who generate a certain amount of power from renewables; those who don’t, face the fine of having to pay for their ROCs.
Tidal basicsTidal farming’s most common technologies are drag devices, or water wheels, and the generally more efficient lift device turbines, which function like windmills. To power 20,000 homes, a small fraction of Scotland’s population of 5 million, a tidal farm of the future would need about 20 connected turbines.
At Aberdeen's Robert Gordon University, Mr. Bryden has circumvented traditional turbine designs. His brainchild, the Snail, is a 15x12 meter (roughly 49x39 feet) anchoring device that uses hydrofoils – what scientists describe as wings that “fly” in water – to generate more than 200 tons of downward force to the seabed. Six dragon-like wings attach the unit to the national grid.
Traditional technologies rely on a turbine and a pillar, which attaches the structure to the seabed, keeping the turbine in place. Each component runs about £60,000 ($111,000). The Snail costs the same to make, but offers significant savings down the road. Installation and “recovery,” or future maintenance, cost upwards of £100,000 ($185,000) per day for traditional technologies, 6,576 percent more than the Snail’s £1,500 ($2,771).
One major reason for the price difference is the depth of water needed: whereas the traditional system has to be transported to, and installed in, deep water, the Snail version works in both shallow and deep waters. It can be transported using just a tugboat and, better, can be used in many more locations.
The first experimental tidal farm, to be launched in 2007, will yield just 5MW at first, enough for around 10,000 homes. While possessing only enough energy to power less than one quarter one percent of Scotland’s population, it would mark a significant first step for the emerging technology.
Channeling the seaScotland has identified Orkney's Pentland Firth and Shetland's Yell Sound – about 330 miles north of Edinburgh – as its best sites for harnessing tidal power. Both have sea channels and are exposed to the Atlantic, making the area a prime location for capturing big tidal movements. An energy test site has already been built using a local investment of 5 million pounds ($9.18 million).
Meanwhile, the competition is heating up, as two English firms are racing to stake their water claim. In the Yell Sound this past summer, Northumbria’s the Engineering Business, an offshore engineering company, tested its 150 kW Stingray technology – a lift device using several underwater windmills – at a cost of more than 3 million British pounds ($5.51 million). Recently decommissioned in order to measure its results, its analysis is scheduled for a mid-March release.
Devon-based Marine Current Turbines (MCT) has tried out its 300 kW experimental turbine in the Bristol Channel. Only one international rival has tested technology in the sea – Norway’s Hammerfest Stroem, the town of Hammerfest’s electricity company. It tested its tidal turbine 18 months ago, but has since been hit by lengthy financial delays. No analysis has been released and industry insiders are dismissing it as "very quiet."
The professor claims small tidal farms could be completed by 2006. “To do this, the Snail technology could be licensed to a developer, or we could create a spin-out firm,” Mr. Bryden says. “Our business plan has profitability penciled in for three years’ time.”
Alternative energy attempts have spotty success in the region: When Britain turned to wind energy during its series of power crises in the 1970s, the U.K. lost out to Denmark because it was slow to create a market. Danish energy giant Vestas built the familiar three-rotor wind turbine, which then flooded the market, forcing British companies to import turbines from across the North Sea.
Other international players like Ireland, Portugal, Canada, Denmark, and Norway are moving toward developing as large a scale commercial market as possible. For Scotland, then, the Snail's pace of development could be key to claiming the power of its sea.