This month has seen two significant developments in plans to harness the power of the waves and the tides off the British Isles. On 2 March 2010, the Regional Development Agency for the South West of England announced the start of the construction of an onshore electricity sub-station at Hayle in Cornwall, so that power from its Wave Hub – a facility to test wave technology ten miles off the Cornish coast – can be fed into the electricity grid (see South West RDA: Next stage of Wave Hub construction underway). And this week, the Crown Estate, the body that administers over half of the UK’s foreshore and all the seabed out to 12 miles, announced the successful bidders in the world’s first commercial wave and tidal leasing round, for ten sites in Scotland’s Pentland Firth and Orkney waters. If all the successful projects are built, they would be 1.2Gw of installed capacity in 2020, 600Mw each from wave and tidal (see The Crown Estate: World’s first wave and tidal energy leasing round to power up to three quarters of a million homes). This is higher than the initial proposed capacity, which was 700Mw. Most of the successful bidders are Scottish or based in Scotland, and there is strong support for marine energy from Scottish politicians The Scottish government, Highlands & Islands Enterprise, Orkney Islands council and the Highland council are all working with the Crown Estate to promote wave and tidal power.
The First Minister of Scotland, Alex Salmond, said when the Crown Estate made its announcement that Scotland could become “the Saudi Arabia of marine power”. Scotland already has a marine energy test centre, the European Marine Energy Centre on Orkney, and this began testing the world’s largest operating wave machine in 2009.
Marine renewables do indeed have enormous potential. However, a sense of scale and proportion is needed. The wave machine on Orkney is only 2Mw. Before it began operating, the largest operational wave device was 1.5Mw, off Portugal (with the technology supplied by a Cornish company). The largest tidal stream project (tidal stream uses underwater turbines and does not require a barrage), in Strangford Lough in Northern Ireland, is 1.2Mw. If all the projects chosen by the Crown Estate are constructed – and that is a big ‘if’ – the Crown Estate estimates that they will produce enough electricity for three quarters of a million homes. This is almost a third of the number of homes in Scotland, so it would certainly be impressive if all these homes got electricity from marine renewables. However, that is only a third of domestic electricity use. Electricity is also used by the public sector, commerce and industry and, in addition, households use gas for heating and oil for transport.
One reason why politicians support marine renewables is that there is less opposition from NIMBYs, since no one lives in the sea. However, the electricity has to come ashore somewhere and NIMBYs are quite capable of opposing electricity substations anywhere near their homes (though not abstaining from using the electricity produced). Swale Borough Council, in North Kent where the electricity from the 1Gw London Array would come ashore, originally refused planning permission for the substation. Therefore, there should be some financial benefit from marine renewables (and offshore wind) to the onshore community where the electricity comes ashore, as there is for communities around onshore wind farms.
Despite this need for perspective, it is exciting that Scotland, Portugal and Cornwall are all seriously committed to marine renewables. Along with wind and solar – particularly concentrated solar power – and biogas, wave and tidal power are essential components in making the world 100% renewable.