Modelling and developing a renewable energy system for the cold stores of a food park in the UK

An on-site renewable energy system is developed and presented in this paper to supply electricity usage of potato cold stores in a UK food park. The system is designed to use the mass of the potatoes to store surplus power from PV when there are days of high solar radiation. It can also be charged from the grid during off-peak time when there are longer periods of overcast conditions. The paper presents results to show energy generated by the PV that can be used in the cooling system, and the storage potential of the potatoes in offsetting grid supply. The dynamic thermal model HTB2 with an energy system extension is employed to design the energy system. The base case representing the existing scenario is validated with previous weekly metering data. The system performance is examined in terms of annual energy performance and long-term cost-effectiveness. The simulation results indicate, 1) the cold store with potato storage is able to maintain the required temperature ranges for most periods when cooling is only powered by electricity from PV during peak-time, and it contributes to energy cost savings and electricity import reduction, but almost no cooling reduction; 2) the system combination of solar PV and off-peak cooling can be paid back within its lifespan, with the most optimal case taking only 11 years. The outcome of the research demonstrates the benefits of the optimized renewable energy system, which provides free or cheap energy supply, reduces industry-related CO2 emission, and contributes to overall energy cost savings. This technique might be applied to other type of food storage, where the thermal mass can contribute to thermal storage. (paper)