Renewable heat is an application of renewable energy referring to the generation of heat from renewable sources; for example, feeding radiators with water warmed by focused solar radiation rather than by a fossil fuel boiler. Renewable heat technologies include renewable biofuels, solar heating, geothermal heating, heat pumps and heat exchangers. Insulation is almost always an important factor in how renewable heating is implemented. Many colder countries consume more energy for heating than for supplying electricity. For example, in 2005 the United Kingdom consumed 354 TWh of electric power, but had a heat requirement of 907 TWh, the majority of which (81%) was met using gas. The residential sector alone consumed 550 TWh of energy for heating, mainly derived from methane. Almost half of the final energy consumed in the UK (49%) was in the form of heat, of which 70% was used by households and in commercial and public buildings. Households used heat mainly for space heating (69%). The relative competitiveness of renewable electricity and renewable heat depends on a nation's approach to energy and environment policy. In some countries renewable heat is hindered by subsidies for fossil fuelled heat. In those countries, such as Sweden, Denmark and Finland, where government intervention has been closest to a technology-neutral form of carbon valuation (i.e. carbon and energy taxes), renewable heat has played the leading role in a very substantial renewable contribution to final energy consumption. In those countries, such as Germany, Spain, the US, and the UK, where government intervention has been set at different levels for different technologies, uses and scales, the contributions of renewable heat and renewable electricity technologies have depended on the relative levels of support, and have resulted generally in a lower renewable contribution to final energy consumption. Leading renewable heat technologies Solar heating Solar heating is a style of building construction which uses the energy of summer or winter sunshine to provide an economic supply of primary or supplementary heat to a structure. The heat can be used for both space heating (see solar air heat) and water heating (see solar hot water). Solar heating design is divided into two groups: Passive solar heating relies on the design and structure of the house to collect heat. Passive solar building design must also consider the storage and distribution of heat, which may be accomplished passively, or use air ducting to draw heat actively to the foundation of