In September 2013 Ofgem issued Draft Guidance: Non-domestic scheme for Metering Placement Examples.

This Guidance refers to new Regulations including:

• Simplification of the metering arrangements
• Air quality requirements for biomass boilers
• Allowing heat to be used for processes other than in a building in certain circumstances
• Allowing accreditted installations to be relocated
• Allowing installations that were used by an installer to gain MCS accreditation to be eligible for the RHI

These simplified metering requirements require only the minimum number of meters necessary to calculate the RHI payment as well as allowing heat loss from external pipework to be disregarded (in certain circumstances) where it is considered to be properly insulated.  In addition, for applicants who can prove that it is either physically or financially 'overly burdensome' to install a heat meter, they will instead be allowed to submit a heat loss calculation in place of installing additional meters.

All applicants with biomass boilers will now need to submit an RHI emission certificate or a valid environmental permit with their application.

Ofgem Guidance includes flowcharts to establish if any of your heat use is ineligible and whether the metering arrangements for your installation is standard or multiple for RHI purposes.

Flowchart A will help determine whether any of your heat use is considered to be ineligible for support under the RHI.  It will also help determine when and how any heat loss from external piping should be measured.

Generally if the heating system uses external piping and:

1.  is NOT properly insulated then it is considered to be an ineligible heat use.  Heat losses should be metered or, if appropriate, accounted for via a heat loss calculation.
2. is properly insulated and any individual lengths are equal to or less than 10 metres then the heat losses from individual lengths are NOT considered to be an ineligible heat use and can be disregarded.
3. is properly insulated with lengths greater than 10 metres and heat loss calculations show that the average annual heat loss from the external piping is less than 3% of the projected annual heat output of the plant then it is NOT considered to be an ineligible heat use and can be disregarded.
4. is properly insulated with lengths greater than 10 metres but heat loss calculations show that the average annual heat loss from the external piping is greater than 3% of the projected annual heat output of the plant then it is considered to be an ineligible heat use.  However, a heat loss calculation can be performed in place of installing additional meters to account for this heat loss.

Flowchart B, in conjunction with flowchart A, will help determine whether your metering arrangements will be considered to be standard or multiple for RHI purposes.

For further advice on heat loss calculations and metering placement please contact Peter James on 01900 870404 or pjames@wjp-ltd.co.uk