CO₂ emissions from Generation, kt

2002	2003	2004	2005	2006
24,458	31,006	28,078	28,406	27,583

2005 figure updated to include CHP data outstanding at the time of publication of 2005 Report

This graph reflects the use of fossil fuel-based generation and includes emissions from all of our power stations and CHP sites. Total CO₂ emissions fell in 2006 partly due to reduced demand following warmer winter weather and partly due to an unplanned outage at Ratcliffe-on-Soar power station.

CO₂ emissions per TWh, kt/TWh

2002	2003	2004	2005	2006
538	651	639	636	655

Includes all wholly and partially owned generation assets including combined heat and power

This graph shows the carbon intensity (the amount of carbon dioxide emitted per unit of electricity generated) of our electricity and heat generation portfolio. The acquisition of the Enfield power station in 2005 meant that our carbon intensity reduced from 2004 to 2005 despite high natural gas prices and the consequent decision to run coal-fired plant in preference to gas-fired plant. Coal remained competitively priced during 2006 despite the downturn in gas prices. As new generation assets are added to our portfolio over the coming years, the carbon intensity of our electricity will reduce.

In 2006, our power stations' CO₂ emissions were 27.5 million tonnes, of which 26.9 million tonnes were tradable under the European Union Emissions Trading Scheme (EU ETS) against an initial allocation of 22 million tonnes. We purchased the difference on the EU ETS market.

Details of other emissions to air are provided here.

Further details of the environmental performance of each our sites are available here and detailed environmental trend data going back to 1990 is available here.