Wind is unpredictable, so wind farms need back-up from more flexible energy sources, driving up costs.
Onshore wind is cost-competitive with other forms of low carbon generation technology. But onshore wind farms suffer various build constraints: the limited availability of suitably windy sites and difficulties securing planning permission.
Building wind turbines offshore avoids these constraints to an extent, but turbines robust enough to withstand the marine environment are more costly to manufacture. Installing and maintaining turbines at sea is also more complex and hazardous than on land, which drives up costs further.
In the first Contracts for Difference auctions in 2015, onshore wind projects were awarded contracts to provide power for around £80/MWh and two offshore wind projects were awarded contracts to provide power at £105/MWh and £119/MWh.
These developments show that the costs of wind power have fallen in recent years. Further reductions may occur, for instance, as experience of installing wind projects increases, or technology improves.