The controversial £20 million installation of ten new wind turbines 100 metres high between Newquay and Truro is complete.
Scottish Power has replaced 15 smaller 49-metre turbines at Carland Cross near St Newlyn East with fewer, larger devices.
The plans were approved two years ago by a planning inspector following a heated public inquiry lasting six days.
The work will triple the wind farm's output from 6MW to 20MW of electricity - enough to power more than 12,000 homes each year.
Simon Christian, UK managing director at ScottishPower Renewables, said: "As our oldest operational site in the UK, it is sad to see the final turbines from the original windfarm being decommissioned. As the first generation of commercial turbines, they have proven to be extremely reliable and the site has performed exceptionally well for two decades, even in its mature operational years. Since 1992 Carland Cross has generated enough clean green electricity to power the equivalent of around 3,300 homes each year, displacing 8,500 tonnes of carbon dioxide.
"The success of the original windfarm is due in large part to the selection of the site. We knew Carland Cross was a good location, with consistent wind speeds and good access. We are pleased to be developing a new project on this site, and we are confident that Carland Cross will continue to make a valuable contribution to renewable electricity generation in Cornwall for decades to come."
Approval of the new turbines had been opposed by local group Residents Against Turbines (RATS), who argued that they would have an unacceptable visual impact.
