Cookers:
The current EU labelling system for cooking appliances was introduced in July 2003 following the success of the energy labelling scheme in place for other domestic appliances. The label again uses the A to G rating system based upon the energy efficiency of the machine, an A rating indicating the most efficient and G the least efficient. Also included within the compulsory label is the energy consumption in kWh (kilowatt hour which is a unit of energy equal to 1,000 watt hours, for example an appliance rated at 1,000 watts - or 1 kilowatt - operating for one hour uses 1 kWh of energy), the cooking capacity in litres, and the type of oven/cooker (small, medium or large). However some ovens are exempt from having to display a label (source: DEFRA), these include: microwave ovens and microwave combination ovens as well as ovens without adjustable temperature control.
A notable exemption to the labelling scheme is gas ovens, due to the difficulty in comparing the efficiency of gas and electric ovens. A direct comparison between kWh consumption would favour electric ovens yet a CO2 emissions rating would favour gas ovens. Currently the testing system is based around the energy consumption of the appliance in preheating to 200°C and maintaining the temperature for one hour, however this is being phased out in favour of a “wet brick” which involves heating a saturated brick from 5°C to 60°C and measuring the energy consumed. A similar test is still being developed for gas ovens however no universal comparison between the two types currently exists. (source: Environmental Exchange Institute).