E.on and Dong Energy's 1GW London Array project in the Thames estuary in south-east England is due to be built in two phases. But planning work on the first 630MW phase revealed a large wintering population of 6,500 red-throated divers, a rare sea bird that breeds in the Arctic tundra but moves to more temperate waters to the south in the winter months.
With the wintering grounds designated a special protection area under the European Birds Directive, the second phase of London Array is now potentially under threat. However, conservation groups the Royal Society for the protection of Birds (RSPB) and Natural England say they are working closely with the developers to evaluate the effect of phase one on the bird population, and are working towards adapting phase two so that renewable energy and wildlife can co-exist.
"The RSPB is a supporter of renewable energy and of offshore wind," said Dave Burges, south-east England conservation officer at the influential group. "But phase two will not go ahead until monitoring work on the effect on the divers is evaluated. The wind-farm site is in shallow water on sandbanks that provide accessible fish and crustaceons for the birds to feed on in winter.
"The birds also sit on the water, unlike wading birds, and tend to avoid man-made structures and shipping lanes, so could be displaced to other habitats where other birds already are," he added.
The RSPB said it wants to establish with the developers how both can co-exist. Burges said that adapting the footprint of the second phase - the spacing of the turbines and their size - could provide solutions. "As a general rule bird habitats tend to be in shallower water where the food is, which are also attractive sites for wind farms," he added. "But we are confident our constructive working relationship with the developers will find a solution for all."
The dialogue currently under way to reconcile birds and turbines could provide a model for future Round 3 offshore wind projects. However, the RSPB says other infrastructure projects such as a proposed new airport in the Thames Estuary would be more difficult to reconcile with environmental concerns.
Richard Rigg, project director for London Array, said that with up to 50 vessels now working on phase one, and with two substations and many of the foundations already in place, the project is progressing on schedule. He added that London Array is now undertaking further bird-habitat study during the first breeding season of activity at the site, and then once the first turbines are in operation, before the second 370MW phase can go ahead.
London Array, a joint venture between E.on, Dong Energy and Abu Dhabi group Masdar, is due to start generating its first electricity in 2012.