The UK is shaping up up to take a leading role in the development of a global wave-power business that could well see £500bn invested over the next 25 years.
Three engineering companies will install small pilot devices off the UK coast over the next 18 months that are expected to produce electricity at costs between 4p and 7p for a kWh – a range that suggests scaled-up projects could compete with conventional forms of power generation.
The present impetus for wave power owes much to a few small companies who persevered with the development of more efficient technologies after the government decided in the early 1990s the concept would be uneconomic and stopped funding it.By 1998, however, a government review concluded wave power could feasibly contribute 30 terrawatt hours a year – about 10% of UK demand – within 15 years for an investment of £10bn.
On a global scale, the potential contribution was assessed at 2,000 TWh/year entailing a capital investment of £500bn. Development resumed, and the momentum has been growing since.
A recent report from theCommons Select Committee on Science and Technology concluded that ‘we can no longer afford to neglect the potential of wave and tidal energy’, and both feature prominently in the Government’s current energy review. There is also mounting interest from potential financiers.
Thomas Thorpe, a consultant in renewable energy and environmental matters at AEA Technology, said the clients he was advising on the issue included four investment banks and two venture capital firms – a sure sign that wave power was now viewed as a commercial proposition. ‘After years of people working in the wilderness, everyone’s gone crazy,’ he commented.
Thorpe said several demonstration schemes employing at least five different technologies would be installed around the world this year – including Australia, Ireland and Portugal -— and these would need to operate for a few months before commercial development took off. ‘I would expect things to really start happening then.’
One of the demonstration projects will be a 2MW floating device in Scotland built by Wavegen, the Inverness-based company that began operating the world’s first grid-connected wave generator last year – the 500kW shore-based Limpet, which uses an oscillating water column to compress air to drive a turbine.
David Langston, Wavegen’s business development manager, said the 2MW project, for which the company received a £1.67m DTI grant last week, would employ a different technology from the Limpet but details are still commercially confidential.
The device will be towed to a location 4km off the Orkney Islands to provide power for 1,400 homes. Langston said it should be operational by late 2002.
Ocean Power Delivery, based in Edinburgh, will also build a full-scale version of the Pelamis or ‘sea snake’ floating offshore generator. This device has five jointed modules that move in relation to each other as they meet oncoming waves with hydraulic rams in each unit to turn a turbine.
OPD has a contract under the Scottish Renewables Order to install two Pelamis units off Islay in early 2003 to supply power to the grid at under 7p/kWh.
The third company that will install an off-shore generator is the London-based Marine Current Turbines, which will deploy an experimental subsea turbine, similar in principle to a wind turbine, near Lynmouth off Devon.
If all these technologies prove themselves reliable and deliver power at the projected cost, the next stage will be the deployment of systems that generate 30-40MW which will dramatically reduce the unit cost of generation – not least because the grid connection costs will be a less important consideration in the projects’ economics (Wavegen and OPD will pay £500,000 to link to the grid in Islay).
Peter Fraenkel, MCT’s technical director, said a 30MW underwater turbine farm could produce electricity at 3p/kWh.
This is clearly the point at which expansion of the sector could really take off, conceivably bringing the DTI’s ambitious 20-year targets within range.