The title of this post is, according to the FT, the answer to the question: How many offshore wind turbines will have to be installed per day by the end of the decade to meet the UK's renewables target? Through 2016 the UK should be averaging one installation per day (see figure above). The FT finds this prospect doubtful:The average rate of offshore installation up to now has been one turbine every 11 days. To hit the government’s target that Britain should source 15 per cent of its energy from renewable sources by 2020, that figure will have to rise to more than two a day by the end of the decade.Offshore wind is one of the most expensive forms of electricity available. The extra difficulties faced by the Round Three developments will make them more costly, unless there are radical improvements in technology.