Developer SSE Renewables has given the go-ahead to its first subsidy-free wind farm, extending the Gordonbush project to 117MW from the current 70MW.

The wind farm, located north-west of Brora in the Scottish Highlands, is one only a few onshore projects to be greenlighted in the UK after government support for the sector was halted in 2015.

SSE Renewable managing director Jim Smith warned that merchant investments in land-based wind power was only viable on “a limited number of the most attractive projects” and would not lead to the build-out needed to meet Britain’s net-zero targets unless Westminster provided revenue stabilisation through access to Contracts for Difference (CfD) auctions “or more robust carbon pricing over the long-term”.

Onshore wind is the cheapest form of low carbon generation and brings job and investment to rural communities. Yet despite the climate emergency, onshore wind construction is at the lowest it has been in a decade,” said Smith.

“We urge the UK government to ensure onshore wind can be developed at the pace and scale set out by [government advisory body] the Committee on Climate Change (CCC) by providing investors with more certainty over the income they will receive for generating zero-carbon power in the longer term."

The CCC has told the UK government that wind capacity needs to expand by at least 1GW a year to achieve net zero emissions targets, reaching 35GW by 2035.

SSE Renewables has named Scottish civil engineering and building contractor RJ MacLeod as preferred supplier of the civil and cabling works for the Gordonbush extension, construction of which will start in March using part of the infrastructure and the grid connection of the original wind farm.

According to analyst Cornwall Insight, there are 4.59GW of onshore wind projects – along with 1.5GW of solar — which are being held back from construction by restrictive planning rules and exclusion from the CfD support mechanism.

These projects are currently searching for subsidy-free routes to market, according to Cornwall Insight, which points out that only 72.9MW of onshore wind and 157.9MW of solar are currently under construction.