| The last few decades has seen a rapid growth in | | | | ground into the house. |
| awareness of the environmental problems associated | | | | The energy comes from underground pipes that are |
| with burning fossil fuels to produce energy. The | | | | buried near the house, vertically or horizontally. A |
| spread of alternative energy use has not been | | | | liquid runs though these pipes. It is pumped down into |
| anywhere near as rapid. Many people have been | | | | the ground then back up into the house, where it |
| prevented from switching to environmentally sound | | | | passes through a heat exchanger. The liquid then |
| options by poor availability, insufficient efficiency and | | | | continues around into the ground again. As it passes |
| high prices of renewable energy systems. | | | | around this loop, its temperature changes. It grows |
| It has been particularly difficult for people to turn to | | | | warmer when it moves underground, absorbing heat |
| environmentally friendly energy production in their | | | | from the warm earth surrounding the pipe. In the |
| own homes. They do not have the resources, in | | | | heat exchanger, it loses this heat to a cooler liquid |
| terms of either funding or space, necessary to build a | | | | that is being pumped around a separate loop. |
| wind farm of put up ranks of solar panels. They have | | | | This second liquid, in its separate loop, is turned into |
| instead been offered small solar panels, solar water | | | | gas as it absorbs heat. The gas passes into a |
| heaters and small wind turbines. These can rarely | | | | compressor, which pushes the molecules of gas |
| provide enough power for the entire home, and they | | | | closer together, raising their temperature even |
| tend to be too expensive for the average family. | | | | further. The ground heat raised it to about 12 |
| Ecofriendly electricity companies are beginning to | | | | degrees Celsius. Compression increases it to over 65 |
| remedy the situation by providing clean energy, but | | | | degrees Celsius. |
| generating power on a small scale is still difficult. | | | | The hot gas is used to heat water and/or air. The |
| Solar water heaters may be the exception. They use | | | | water which it has heated can be used in the home, |
| the sun's heat directly, to warm water for use in the | | | | just like hot water produced by any other method. It |
| home. They are affordable and work well, particularly | | | | can also be used in the heating system (e.g. |
| during the summer. Solar heaters can provide hot | | | | radiators). The heated air is pumped through a |
| water and heat the home. | | | | system of ducts to warm the house, while a second |
| Clean methods of energy production for domestic | | | | duct system brings cooler air back to the heat |
| heating are an important part of the UK's efforts to | | | | exchanger. |
| become more environmentally friendly. About 40% | | | | During the summer, when the house is hot and the |
| of carbon dioxide emissions are produced by the | | | | ground cool, the heat exchange can be reversed to |
| heating of buildings. | | | | cool the house. |
| An alternative method of heating the home that is | | | | Geothermal systems use pumps that run on |
| more efficient and reliable than solar water heaters is | | | | electricity, so while this power source is still based on |
| now spreading through the UK. This technology has | | | | fossil fuels they are not entirely environmentally |
| been available for about 50 years, but until recently, it | | | | friendly. The systems are very efficient, however, |
| has not made much of an impression in this country. | | | | producing three to four kilowatts of heat for every |
| Geothermal or ground source heating takes heat | | | | kilowatt of electricity used. This means that they |
| energy from the ground and distributes it through the | | | | reduce the use of other types of energy. If a |
| house. It can also heat water for domestic use, and | | | | renewable electricity source is also used, then the |
| cool the home during hot weather. It can be relied on | | | | system becomes completely clean. |
| throughout the year, requires little maintenance and is | | | | Geothermal heating systems are efficient and reliable. |
| not impossibly expensive. | | | | They can heat water and maintain a steady |
| These systems redistribute heat through a series of | | | | temperature in the home, heating it in winter and |
| pipes running underground and through the house. | | | | cooling it in summer. They can work with traditional |
| The temperature underground remains much more | | | | home heating systems such as radiators and |
| constant than that above ground. This means that it | | | | underfloor heating. A geothermal system can reduce |
| is warmer underground in winter and cooler in | | | | energy bills by 70%. The initial cost will be high, but it |
| summer. A geothermal system takes advantage of | | | | can be reduced by government grants, available |
| this fact by redistributing heat energy from the | | | | under the Clear Skies scheme. |