CO2 emissions from electricity production

The Carbon Emissions from electricity production using fossil fuels for electricity production results in high CO2 emissions, a major contributor to global warming.

Approximately 43% of electricity production in Scotland is produced by burning fossil fuels.  The distribution between the fuels used in the major power generating stations is shown.

Electric Resistance Heating in Buildings

Direct electric space and water heating in new developments has been in use for several decades. Usually in cases where there was no original gas supply to the building. Social landlords frequently specify electric space heating to reduce the requirement for gas appliances to be inspected once a year. In additional to high CO2 emissions, direct electric, including electric storage heaters, are generally more expensive to run.

Electric space heating is easier and cheaper to install than other heating systems, however the notional CO2 emissions as a result of running this type of system are high.

Why does the use of Direct Electric Heating produce a poor EPC rating?

Although electric resistance heating in a building is almost 100% efficient at point of use, electricity generation at power generation source and distribution / transmission losses are lead to greater inefficiency.

At present, a substantial amount of CO2 emissions are generated when producing electricity through burning fossil fuels such as coal or oil fired power stations. The efficiency of power station generation varies widely with the technology used.

The average global efficiency of coal fired power stations is 28%. So called “supercritical” coal plants can reach efficiency levels in the mid-40’s, and the latest coal technology, known as ultra supercritical or IGCC, is capable of efficiency levels up to 60%. The most efficient gas-fired power stations achieve a similar level of efficiency. Even at 60% efficiency there is a tremendous amount of energy left behind in the generation process.  That represents a higher cost of production for the generator, as well as a substantial waste of limited resources.

There is significant economic and ecological incentive to improve the efficiency of power generation so that more of the energy content of the input fuel is carried through to the output electricity.

More information on this topic including information on the worlds most efficient coal power station can be found by going to the World Coal Association website here

Distribution Losses

Distribution losses are defined as the difference between the electricity entering the distribution network and leaving it arise for technical and other reasons. Distribution losses represent approximately 5% (OFGEM) of units distributed.

The Effect on a buildings EPC Rating

At present partly due to the makeup (fossil fuel, hydro, nuclear) of grid supplied electricity, using direct electric resistance heating generates high CO2 emissions and significantly worsens the EPC rating of a building.

Alternatives to Direct Electric Heating For properties that do not have a gas mains supply alternative heating types to direct electric heating include include biomass boilers, air, ground or water source heat pump technology.

Future Electricity Production

By 2020, Scotland aims to generate 40% of its electricity needs from renewable sources and this will reduce the carbon content associated with the use of electricity. While future plans for some of Scotland's major power stations have been made known, these may change in response to market conditions. Similarly, plans for new power stations are commercial decisions for the electricity generation sector. Their decisions will take into account factors such as: future energy prices, electricity demands, the regulatory environment and new technical developments.