Smart control system technologies for combined heat and power (CHP) units are not previously reported in literature, and have potential to generate significant savings. Only minimal capital investment is required in infrastructure and software development. A live cloud-based solution has therefore been developed, and installed in a real UK supermarket store, to optimise CHP output based upon predicted price forecasts, and live electricity and head demand data. This has allowed validation of the optimiser price forecasts, and predicted cost savings, and a model of the optimiser has therefore been applied to three case study sites. The model itself has also been validated against the installed optimiser data. The pre-feasibility analysis undertaken indicates cost savings between 2% and 12%. CHP units sized within the feasible operating range, above a part load level of 0.65, generate the greatest percentage savings. This is because the optimiser has the greatest flexibility to control the CHP output. However, larger units, even though less nearly optimal, may actually generate greater overall savings and would therefore be targeted for earlier optimiser implementation. Installation costs are not expected to vary greatly from site-to- site. Some stores, though, show no material improvement over the existing control systems, demonstrating the value of the pre-feasibility analysis using the model. Though waste heat increases significantly with all strategies, the propensity to sell this heat within the UK is likely to improvein the near future.