David Cameron offically opened the world's largest off shore windfarm today - describing it as ''great for Kent and great for Britain." He was speaking in Margate after touring the vast site - by helicopter.
The London Array is in the outer Thames Estuary - 12 miles from the coast of Kent and Essex.
There are claims tonight that wind turbines and other forms of green energy will hike up energy bills - something government ministers deny. Watch Derek Johnson's report.