One of Britain’s oldest onshore windfarms will soon be “repowered” so it can generate five times as much green electricity as it did in 1995 – with almost half as many turbines. The owner of the Hagshaw Hill windfarm, ScottishPower, began dismantling 26 turbines on its site in rural South Lanarkshire on Wednesday. The renewables developer will replace the ageing turbines with 14 larger versions that use updated technology to generate renewable energy more efficiently. The tip of each new turbine will stand at a height of about 200 metres (over 650ft), compared with the older turbines that had a height of 55 metres, according to ScottishPower. The windfarm will also be equipped with a battery storage facility of about 20 megawatts to help make better use of the green electricity. The “repowering” project means the 16MW windfarm, which was the first commercial windfarm to operate in Scotland when it began generating 28 years ago, will have a capacity of 79MW once complete. Charlie Jordan, the chief executive of ScottishPower Renewables, told the Guardian that there was “massive potential” to increase the UK’s renewable energy capacity by repowering its older windfarms using new technology. “Wind power technology has improved so much in the last 30 years. Three modern wind turbines could produce as much power as the whole [Hagshaw] site,” he said. “Although Hagshaw is our oldest site, there were a number of windfarms built in the late 1990s which are coming to the end of their operational lives. We have a dozen more to repower over the next three or four years.” The local community had been “really supportive” of the project, which would employ up to 100 people when work reached its peak, he said. Currently, repowering an existing windfarm is subject to the same planning consent process as building a new onshore windfarm from scratch, according to Jordan. “At the moment, we have to start right at the beginning again,” he said. ScottishPower is calling on the government to streamline the planning process for existing windfarms to take into account the lower risks of developing in an area that is well understood by developers and supported by local communities. Barry Carruthers, a director at ScottishPower Renewables, said: “We’ve worked in this area for almost 30 years, we know how good this site is and now we’ll be able to produce enough electricity to power almost 61,000 homes each year – almost half the homes in South Lanarkshire.” ScottishPower expects to continue dismantling Hagshaw Hill over the summer and into early autumn. The first new turbines are expected to arrive at the site in May 2024, and the repowering will be complete by early 2025.