Nina Dungworth, Consulting Engineer at FairHeat, is working with developers to review and provide quality assurance throughout the design, commissioning, installation and operation of their heat networks. Nina was invited to present her research at the Smart Energy Systems Conference 2024 in Aalborg.

Abstract

Heat networks are a key part of the UK Government’s strategy to reach net zero emissions by 2050 and the heat network market is set to grow rapidly. To aid this transition a regulatory Heat Networks Technical Assurance Scheme (HNTAS) is to be put in place to ensure high standards of design are met.

One of the core principles for HNTAS is that it should be proportionate, with the effectiveness of the assurance process balanced against the cost of compliance.

Heat networks in the UK have historically been subject to significant peak load and network pipework oversizing. Research has been undertaken to determine the cost saving opportunity to developers as result of correctly sizing schemes, through having a technical quality assurance (TQA) scheme in place. This research contributes towards ensuring the scheme is cost effective.

To facilitate this, data was taken from existing networks that have been audited as well as new build schemes that have been through a design review. The opportunity to improve the design of those schemes provides an initial proxy for the gains that would be expected from a TQA process.
The direct cost saving opportunities of assurance have been identified through calculating the potential reductions in CAPEX & equipment servicing costs related to correctly sizing heat network pipework and heat generation equipment. For heat generation equipment, various energy strategies have been assessed throughout the research. These schemes are 100% gas boiler, 95% heat fraction ASHP & gas boiler top up and 100% ASHP only.

In conclusion the following cost saving opportunities have been identified:

• Correctly sizing network pipework has expected CAPEX savings of c.£380/dwelling
• Correctly sizing heat generation equipment has expected CAPEX savings of c.£530/dwelling for a gas boiler only scheme, c.£1,300/dwelling for a 95% heat fraction ASHP & gas boiler top up scheme and c.£2,500/dwelling for an ASHP scheme.
• The expected equipment servicing cost saving NPV was calculated to be c.£120/dwelling over a typical 25 year equipment life span.