FEBRUARY 2002 - NO. 124

Better infrastructure is key to agreen energy producton

Wild, wet, windy weather is part of what makes North West Sutherland special, but it doesn’t pay the bills, writes. Not just yet, anyway. However, wind and waves are sources of “renewable power”, the capture and sale of which could bring a new energy boom to the north of Scotland. The only constraint seems to be a few weak circuits...

A key player in the Highlands energy scene is the world-leading wave-power company, Wavegen, based in Inverness, which is attracting considerable interest and multi-million investments as a result of its brilliant LIMPET generator recently installed on Islay.

Like its namesake, the LIMPET (Land Installed Marine Powered Energy Transformer) is firmly attached to shoreline rocks. “It acts like a sea cave with a blow-hole” explains David Langston of Wavegen. “As the ocean swell rises and falls, the air in the cave is pushed up and sucked down, and this air pressure drives the turbine.” The Wells Turbine, invented by Professor Alan Wells, founder of Wavegen, uses the principle of a bird’s wing to keep a rotor turning in a single direction as the air goes in and out. The turbine then drives an induction machine generating electricity suitable for transfer to the national grid.

“The great thing about wave power is that waves are a concentrated form of wind energy, and the sea transmits swell generated by wind and storms hundred of miles away. Unlike wind generators, the LIMPET device can continue operating no matter how big the waves get and because it is enclosed there’s virtually no noise,” claims Mr Langston. The visual impact is also minimal because it is built into the rocky shoreline. Like wind, however, it will not generate in calm conditions, and he admits that the building work has a negative environmental impact. “But one of its advantages is that it helps to aerate the water which is good for marine life.” It could also be good for local economies. “Sixty-seven per cent of the cost is in building the capture chamber on site so there is a lot of local construction work. We also have a contract with a local company on Islay for regular checking and maintenance.” The total cost of setting up a generator depends on the size of the development, and because some costs like grid connection and project management are pretty much fixed, there’s a real economy of scale. “It could be worth trying to put in multiple installations,” recommends Mr Langston.

Similar advice comes from Atlantic Energy, which is helping the Melness Crofters Estate develop a proposal for a windfarm. “Think big!” urges Atlantic chairman Charmian Lark. “There’s a huge potential on the west coast of Sutherland for wind and wave power. Don’t let your ideas be limited by the current infrastructure.” There are certainly good reasons for considering windfarms up here, not the least the fact that in Scotland they earn community councils £1,000 per MW every year.

However, there will need to be a sea-change in the way the grid is managed in North West Sutherland before electricity generation will be viable on a big scale. As David Langston puts it, “there is tremendous scope for Sutherland. The wave climate is good. But the infrastructure issue is what makes it difficult.”

There are two kinds of problem with the electricity infrastructure. Firstly, the electricity supply to some remote areas is only single phase, but most generators produce 3-phase output and therefore need 3-phase power lines. The Melness crofters face this problem and overcoming it will involve taking a dedicated cable from their site across the Kyle of Tongue causeway to the Coldbackie substation in Tongue where they can connect to the 3-phase grid. But this is expensive. The second problem is that in some remote locations 3-phase lines often cannot take significant power inputs. Jim Molley of Scottish Hydro-Electric Power Distribution Ltd (S+S) explains. “Historically the power lines were designed to feed very low density demand, and as a result some of the remote locations in your area have weak circuits.” According to David Langston, Wavegen’s Islay installation has the same problem. “We have a 500kW capacity but we can only supply a maximum of 150kW due to the grid being particularly weak at Portnahaven, which is the end of the line.”

Upgrading the grid infrastructure is clearly the key issue to make significant renewable generation viable for North West Sutherland.

There are plans afoot for what could be major advances for northern Scotland, because the UK government has introduced a Renewables Obligation, whereby electricity suppliers must source at least 5% of their power from renewables by 2003, and 10% by 2010. Scotland already produces an excess of electricity of which 13% comes from renewables, mainly hydro. The Scottish Executive aims to increase that to 18%. A new study for the executive reveals that to achieve this target will require grid reinforcement in the Highlands costing £130 million.

A major constraint is that the interconnector to England does not have spare capacity, so if we generate even more power, how will we get it south of the border to sell it? Recognising this inadequacy, an ambitious plan is being promoted by Secretary of State for Industry and Energy, Brian Wilson, for a huge development of renewable generation capacity coupled with a west coast undersea interconnector and cable system “to connnect parts of the western seaboard of Scotland...directly to the national grid.” The big question is, will North West Sutherland be one of those parts? Answer on a postcard please, Mr Wilson.

Most of the talk so far has focussed on the other side of the Minch, with proposals for a vast 300-turbine windfarm, a major wave power scheme and conversion of the oil works at Arnish Point on Lewis to a wind turbine and tower manufacturing plant with the creation of 150 jobs. There is also talk of offshore wind and wave schemes. But all of this depends on the interconnector scheme.

Charmian Lark is adamant that the interconnector could be good for the North West. “The scheme will have to prove itself three ways, economically, technically and politically, and it is the political argument that needs to be made for Sutherland.” Her view is that attention could be drawn to the Sutherland potential through some big generation proposals in order to ensure the plans include an undersea branch to this part of the coast.

At the moment all the big ideas are coming out of Stornoway, but mainland connection has not been ruled out. A spokesperson for the Department of Trade and Industry predicts that “there is a fighting chance that major new infrastructure will happen on the west coast of Scotland” but he says there are two big questions. “First, how do we collect lots of of small generation schemes together to get ‘lumps of power’ large enough to merit undersea transmission? And secondly, who will pay for it?” That’s the question on everyone’s lips.

lll A new planning advice note, “45²”, announced last week by the Scottish Executive, gives details of the various types of technologies that are being introduced, such as wind and wave power, and the planning issues likely to arise with their development. Specific case studies highlight initiatives across Scotland showing the potential economic and environmental benefits these can bring, particularly to rural areas.

— Mandy Haggith

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