Britain needs to spend more than £110bn on new electricity supplies to keep the nation's lights on, the Government has claimed.
Energy Minister Chris Huhne has warned that with ageing power stations closing down, urgent market reforms are needed.
One of the key proposals in a White Paper published on Tuesday, is the introduction of contracts which guarantee long-term stable prices for electricity from low-carbon sources.
These include nuclear power stations and offshore wind farms.
If the price of electricity outstrips the prices guaranteed in the contracts, companies will have to pay back the difference, preventing a windfall for low-carbon generators.