Informing efficient heat network design: Peak demand, diversity and network sizing

Heat networks (HN) play a key role in strategies proposed by the UK’s Committee on Climate Change, and evidence-based standards are recognised as essential for good design and operation. Collaboration across industry has culminated in technical standards, however, evidence has shown that methods currently recommended for estimating demand diversity, widely used in the UK, tend to oversize networks and lead to avoidable thermal losses. This study uses high-frequency data from a recent UK case study HN to investigate the limitations of these methods and to explore how data from existing networks can be used to inform the design of new networks. Results show that peak demands are adequately captured at a resolution of 10 min, a useful benchmark for data-informed network sizing. An assessment of oversizing relative to current sizing methods shows that the case study may potentially be oversized by 52% to 140%. The agreement between measured total peak demand and domestic hot water (DHW) demand design estimates suggests that inclusion of the space heating (SH) component in the design estimates may be unnecessary. The empirical demand curves developed in this work may be a useful reference for designers, as part of a larger empirical evidence base.