Contains the full lesson along with a supporting toolkit, including teachers’ notes.
Over the last few decades there has been a growing public awareness of the need to make more efficient and equitable use of the world’s non-renewable resources – fossil fuels and natural minerals. Carbon dioxide (CO2) is produced when fossil fuels are burned, and so using fossil fuels contributes to the greenhouse effect and climate change. As oil and gas reserves decline and CO2 reduction is demanded, we will need to use energy more efficiently and rely increasingly on renewable energy resources such as biomass, solar, hydroelectric and wind energy.
Energy use in Ireland
Domestic energy accounts for more than a fifth of Ireland’s total energy use. About 60% ofdomestic energy is used for space heating and 24% for heating water. Just 3% is used for cooking and 13% for lighting and for appliances such as washing machines, TVs, etc. While many domestic appliances can be made more energy efficient others are difficult to improve, particularly those that require heat – e.g. tumble dryers, hair dryers and toasters.
Heating and Insulation
By far the best way to save energy in the home is to save on heating. In terms of the fabric of the structure this can be achieved by:
Heat is lost from a house by conduction through the floor, walls, windows, doors and roof. The conductive efficiency of such elements is usually expressed in terms of U-values. The external walls of a house typically comprise several layers such asconcrete, insulation and plaster. These resist the flow of heat at different rates. The greater the thermal resistance, the lower/better the U-value. The units are watts per square metreKelvin (W m-2 K).