The owners of the UK's first wind farm say they want to generate two-and-a-half times more power.
Good Energy wants to replace the ten 30m (98ft) high turbines which have been at the site for 26 years, by 90m (295ft) high ones.
The company bought the pioneering project in Delabole in Cornwall from farmer Peter Edwards in 2003.
The wind farm currently supplies power to about 1,500 homes. Any change would need to get planning permission.
Juliet Davenport, chief executive of Good Energy, said in a statement: "Delabole wind farm has shown that wind power is a great source of sustainable, clean energy.