Prime Minister Tony Blair announced the plans in what's called the Energy White Paper - a report which sets out policies which could become law.
Greener power
The paper says 10% of electricity should come from renewable - or green - energy by 2010 and hopes that will rise to 20% by 2020.
At the moment, only 7% of electricity comes from green energy.
It's hoped the plans mean greener ways of making power will cut the amount of carbon dioxide released into the atmosphere to 60% of 1990 levels by 2050.