When the Danish energy group Orsted raised £2bn in November from the sale of a 50% stake in the world’s biggest windfarm, the Walney Extension project off the coast of Cumbria, to the Danish pension funds PKA and PFA, it was only the latest in a string of big-money deals for wind turbines.

The utilities and power companies that build the windfarms are increasingly selling them off to pension funds and fund managers that are delighted to have found a source of just the kind of long-term, safe investment they want.