Offshore wind costs have already gone up in the last few years because of the move to deep water. We think costs will peak in the next couple of years and then fall, as improvements in installation knowhow, foundations and turbine technology outweigh the extra costs of going to deeper and deeper water.
Offshore wind projects would simply not be built at the moment without support provided by the roc scheme, or after 2017 the contracts for difference feed-in tariff scheme. However the government hopes that by supporting offshore wind now, it will make possible a big reduction in costs over the next 15 years and also help create a world-leading industry in the UK.
Read more: http://www.theengineer.co.uk/energy/in-depth/your-questions-answered-the-london-array/1017519.article#ixzz3YIq9o1mD