Evaluating CHP management and outputs using simple operational data

In cities where there are a plethora of buildings that require both thermal and electrical energy, a cogeneration system may be the optimal solution to satisfying such a demand. Combined Heat and Power (CHP) systems fit this role well. Advantages of CHP installation, whether individually or as part of a District Heat Network, are the economic and low-carbon benefits of on-site electricity generation. However, CHP systems which are not properly sized could easily fall below the designed performance and hence fail to produce the predicted benefits. Poor management of a CHP system where it is operated outside of optimal conditions can also result in a similar effect. This study has been undertaken using a 6-year dataset collected by a Local Authority (LA) from a CHP-led heat network. This type of network is categorised as an ‘Option 2B’ scheme under the CIBSE Heat Networks: Code of Practise (CIBSE CP1) for the UK. Local Authorities in the UK are under increasing pressure to reduce spending and prioritise staff workloads to core tasks. Whilst data from the network is collected remotely, there is limited capacity for LA employees to regularly interrogate the data to look for anomalies or inconsistencies against historical data. The authors review collected trends and events and discuss the benefits of regular interrogation of a small number of datasets to monitor a CHP-led heat network. The results show that for an extended period, the studied CHP electrical output fell by around 30% and was not quickly rectified. The fall in output resulted in an estimated loss of revenue for Local Authority of £18,500. The paper highlights the importance of a simple method to review key operational data from a CHP-led system and ensure consistent management and output.