How are solar and heat pump hot water systems rated?
The Office of the Renewable Energy Regulator (ORER) rates solar hot water systems and heat pump hot water systems by awarding Renewable Energy Certificates (RECs) to each available model. BASIX uses these RECs to determine the performance of these hot water systems: the more RECs, the better the system. For solar-gas and solar-electric hot water systems, more RECs are generally awarded for larger collector areas, more efficient collectors, and better thermal insulation of the tank and pipes. In the case of heat pump systems, higher RECs are generally awarded for better tank insulation and higher efficiency compressors. Typically, gas-boosted solar hot water systems will score more RECs than electric-boosted solar systems, which in turn will usually score more than electric heat pump hot water systems.
