| The Renewable Heat Incentive (RHI) is expected to commence in April 2011. It will provide an annual cash back payment for renewable heating systems such as heat pumps and solar systems installed after 15 July 2009. It will apply to home owners, private landlords, housing associations, social landlords, local authority buildings, community organisations and businesses. The RHI has been calculated by the government to provide a 12% return on investment on heat pump installations and a 6% return on solar thermal systems. Payments will be made annually for between 18 and 23 years. The value of the payment will depend on the technology installed and the size of installation. Very large commercial schemes (> 350kW) will have meters to measure the amount of kilowatthours (kWh) of heat produced. All other schemes will be based on the "deemed” number of kWh: the reasonable annual heat requirement that the installation is intended to serve. Some examples of the anticipated annual cashback are as follows: Technology Output Typical building £ per annum Number of years Ground source 8kW Medium domestic 1,120 23 Ground source 14kW Large domestic 1,960 23 Ground source 30kW 600m2 building 4,200 23 Ground source 100kW 1,200m2 building 11,000 20 Air source 8kW Medium domestic 1,200 18 Air source 14kW Large domestic 2,100 18 Air source 30kW 600m2 building 4,500 18 Air source 100kW 1,200m2 building 4,000 20 Solar thermal 4m2 Medium domestic 285 20 Solar thermal 6m2 Large domestic 401 20 | 
