The size of the UK’s plans for offshore wind became clearer this week, when the government gave consent for the largest offshore wind farm in the world.

Dogger Bank Creyke Beck will sit in shallow water in the middle of the North Sea, 131 kilometres (81 miles) from the UK coast. It will cover an area of 8660 square kilometres, only slightly smaller than the country of Puerto Rico, which is 8870 square kilometers, and almost exactly the same size as Corsica.

The project forms part of the UK’s ambitious offshore building program. The UK is the world leader in offshore wind, and already has more offshore installed capacity that the rest of Europe combined.

Dogger Bank Creyke Beck will have an installed capacity of up to 2.4 gigawatts, enough to power 1.8 million households, and supply around 2.5% of all UK electricity.

It would be the second largest power generator in the UK after the Drax coal-fired station in North Yorkshire, which produces the 3.9 gigawatts of power, according to Forewind, the consortium of British and Norwegian energy companies behind the project.

That is, if it gets built. The project gained consent from UK energy secretary Ed Davey this week, taking it a step closer to actually being erected, but the process is a long one. The “pre-construction phase” is dues to last until 2019, and the construction phase stretches out to 2022.

Moreover, uncertainty in the subsidy environment is making projections more than tricky – like “squaring a circle,” according to one person in the industry.

It isn’t clear how much money will be in the yearly subsidy pot, for which energy projects have to bid. A UK general election in May could return a government more or less commited to renewable energy than the one in place. And even without regime change, it’s been an uncertain few years.