Optimisation of stand-alone hybrid energy systems supplemented by combustion-based prime movers

A comparative analysis is undertaken between a baseline PV/Batt system, meeting a dynamic load profile, and systems hybridised with supplementary combustion-based prime movers such as Internal Combustion Engines (ICEs) or Micro Gas Turbines (MGTs) of 30–65kW rating. This study sheds light for the first time on a number of research questions not addressed in earlier studies. The main contributions of the work are namely to: (i) analyse the effects of the start-up threshold and the type of supplementary prime mover on the Cost of Energy (COE, $/kWh), lifetime CO2 emissions, and (unrecovered) waste heat for a specified reliability (Loss of Power Supply Probability-LPSP); (ii) investigate the effects of including the transient start-up periods of prime movers on systems sizing; and (iii) look into the effects of using two smaller sized (tandem) supplementary prime movers versus a single larger one on the operational characteristics. The research also analyses (iv) the effects of the methods used (e.g. temporal resolution of simulations, Genetic Algorithm (GA) population size) on the COE, lifetime CO2 emissions, and (unrecovered) waste heat.