The Renewable Heat Incentive (RHI) is designed to only support the generation of heat where it is both usable and useful. The main examples would be heating a room, heating hot water or providing heat for an industrial process.
Meters are required to provide the data to ensure that the RHI payments are correct. Ofgem have quite strict requirements in terms of the types, accuracy, number and location of heat meters. Multiple meters are required if the system is classified as a 'complex system' or if there are 'ineligible loads' present.
Heat meters are available as single 'packaged' units or as separate components. However, in all cases the meter consists of 3 key elements:
- Sensor to measure the flow temperature
- Sensor to measure the return temperature
- Meter to measure the flowrate of fluid through the pipes
Ofgem require that all meters are accurate to within 2% and certified as Measuring Instruments Directive (MID) 2004/22/EC Class II compliant. In addition, the temperature sensors and flow meters must be properly calibrated under the full range of operating conditions.