The Renewables Obligation requires licensed electricity suppliers to source a specific and annually increasing percentage of the electricity they supply from renewable sources. The current level is 9.1% for 2008/09 rising to 15.4% by 2015/16. This is set out in the Renewables Obligation Order.
It is expected that the Obligation, together with exemption from the Climate Change Levy for electricity from renewables, will provide support to industry of up to £1bn per year by 2010.
At the end of 2007 generation from renewable sources eligible under the Obligation stood at 4.9%. This rises to 5% if non-eligible sources are included. Source: BERR Energy Trends June 2008
Eligible renewable sources are listed in the following table:
Hydro exceeding 20 megawatts declared net capacity (dnc)
Only stations commissioned after 1 April 2002
Hydro 20 megawatts or less dnc
Co-firing of biomass
Yes. (There are no restrictions on the amount of co-firing a generator can undertake. However, suppliers can only meet 10% of their obligation from co-fired ROCs.)
Tidal and tidal stream power
Type of Generating station
Waste that is purely biomass
Energy crops, agricultural waste and forestry material
Pyrolysis, gasification and anaerobic digestion
Eligible for the biomass fraction of waste
Combined Heat and Power (CHP)
Eligible for the biomass fraction of waste produced as good quality CHP 
Eligible  (There are no restrictions on the amount of co-firing a generator can undertake. However, suppliers can only meet 10% of their obligation from co-fired ROCs.)
The Obligation is administered by Ofgem. Further information on the Obligation is available from the Ofgem website.
The Office of Gas and Electricity Markets
London SW1P 3GE
Fax: 020 7901 7387
The Renewables Obligation (Scotland) and consultation documents are available from the Scottish Executive - Consultations website.
Information on Northern Ireland is available from the Department of Enterprise, Trade and Investment website.
Renewables Policy & Development
Department of Energy & Climate Change
1 Victoria Street
London SW1H 0ET
Tel: 020 7215 0988