Heating and cooling are typically extremely energy intensive technologies. In the United Kingdom the majority of heating in our homes and buildings is provided by burning natural gas. Renewable energy technologies such as solar heating, or heat pumps provide a sustainable low carbon alternative. Condensing boilers, and combined heat and power (CHP) also offer significant energy savings. In this circumstance energy that would have otherwise been wasted (which happens in traditional power plants) is instead used by the local community via a district heating scheme. Alternatively, a micro CHP system (such as a residential fuel cell, or Stirling engine) produces both electricity and heat to serve a local heat demand i.e. for a particular building. Energy efficiency technologies such as low carbon ventilation solutions can reduce the energy demands of buildings. - Description added by: David Lockie