The proposed structures would stand up to 200m high, making them the tallest onshore turbines in the UK and towering 70m above Scotland’s highest building.
They will be built on the isle of Lewis at two wind farms being developed by Lewis Wind Power (LWP), a joint venture by energy giants EDF and Wood Group.
The firm has already been granted permission to build a total of 91 150m-tall turbines – 45 at Uisenis, on Eishken estate in the Pairc area of Lewis, and 36 at the Stornoway scheme, on the outskirts of the main town.
But the developers say increasing the scale of the turbines will reduce the number required and generate more energy.
However, locals have reacted with anger over the new plans, unveiled on Monday.
Concerns have also been raised that the additional power generated by the massive turbines could supply almost the entire capacity of a proposed new interconnector cable that would transport power to the mainland, meaning no more community schemes could link up to it.
Calum Macdonald, former Western Isles MP and developer of the three-turbine Beinn Ghrideag community wind farm, described the scale of the proposed turbines as “simply staggering”.
Talking to Hebrides Writer blogger Katie Laing, he said: “These are the same size as the gigantic offshore turbines that are now being built in the North Sea.
“They are out to sea for a good reason, which is that their enormous size is thought to make them unacceptable anywhere onshore, far less near a town like Stornoway or near an iconic location like Loch Seaforth.”
Beinn Ghrideag is owned by the Point and Sandwick Trust and raises around £900,000 a year for local causes.
Rhoda MacKenzie, spokeswoman for four common grazings committees who want to develop their own community schemes, has warned the turbines will be “intrusive” and could put off visitors the area.
“When it starts getting into super-turbines, that’s intrusive,” she said.
“It’s intrusive for the people that live near them. It’s intrusive to the landscape.
She added: “It’s going to have a detrimental effect on tourism.
“The largest wind turbines in the UK? I hardly think that’s going to bring people here.”
The developers have defended the new proposals, which they say could be key to the interconnector being built as there would be a guarantee of large-scale power generation.
Will Collins, project manager for LWP, said: “The benefits from developing and exporting wind power from Lewis will only become a reality if island projects win contracts in a competitive auction for low-carbon electricity.
“It’s therefore important that we look at all the options before deciding what we think gives the two wind farms the best possible chance of success.
“If we do reach the stage of considering fresh planning applications then we will be actively seeking the thoughts and views of local residents and stakeholders at a series of exhibitions and through a wider consultation process.”
The Tories have ended subsidies for onshore wind schemes, but in their 2017 general election manifesto said an exemption would be made for developments in the remote Scottish islands as long as they “directly benefit the local communities”.
This means LWP could bid for subsidies under the “contract for difference” scheme, which guarantees a minimum price for electricity.
Scotland’s tallest building is the 127m tower at Glasgow Science Centre. Edinburgh’s famous Scott Monument stands a mere 60m. The Shard in London is the UK’s tallest building at 306m.
The Burj Khalifa hotel in Dubai is the world’s tallest, dwarfing everything else at a staggering 830m – although that is due to be overtaken by the 1,000m Jeddah tower when it is completed in 2020.