Falling demand, lower natural gas prices and the expansion of offshore wind should keep UK electricity prices close to their current levels until 2020, according to New York-based rating agency Moody's Investors Service.

Amid fears of a looming capacity shortfall, many market participants expect the country's electricity prices to rise sharply over the next few years. That view is shared by the UK Department of Energy and Climate Change, which puts the price of wholesale electricity at £61–67 (