Metering And Billing Of Ambient Loop Heat Networks

There is uncertainty in the market as to the metering requirements for ambient loop heat networks. Some manufacturers have stated that it is not a requirement to meter final customers connected to these systems. However, we would strongly recommend that all customers are metered for heat and cooling consumption delivered from ambient loops.

Ambient loops circulate low grade heat around a building at approximately 15-25°C which is upgraded by final customer equipment (e.g. a water source heat pump or variable refrigerant flow system). Efficient customer heat pumps will draw a significant amount of energy from the ambient loop which will, in most cases, be produced by a central heat pump and incur substantial fuel costs.

Although some manufacturers have stated that these networks are exempt from the requirement to meter final customers, as per Regulation 9 of the Heat Network Metering and Billing Regulations (2020), we strongly recommend that meters are installed and used for billing of customers regardless of this potential exemption for the following reasons:

• It is not fair or equitable for final customers to pay a fixed charge for variable energy consumption. Doing so may lead to future challenges and dissatisfaction from customers, particularly those who use less heat than others.
• The absence final customer meters removes the ability to assess network performance and efficiency, removing a vital tool from the network operator to demonstrate value for money to its customers.
• A change in approach from the regulator could lead to a requirement for very costly retrofitting of heat meters.

In some cases, it may not always be appropriate to meter final customers. For instance, if the heat on the ambient loop is coming from a free source (ground water, river water, waste heat etc.) rather than a heat pump. Due to the bespoke nature of ambient loop systems, each design must be reviewed in isolation and, where necessary, early contact should be made with the OPSS to seek approval for the metering strategy.