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Demand side management (DSM) strategies can be used to reduce customers’ demand at peak times, change the timing of end-use consumption from high to low-cost periods and increase consumption during off-peak periods. They can be implemented by using the energy flexibility available in the final users’ applications, energy storages or control systems to turn on/off end-users’ devices when required. Being intensive energy consumers because of a high electric energy demand (refrigeration accounts for about 40 % of the yearly energy consumption), supermarkets are ideal candidates for a DSM approach. This work shows the results of a DSM analysis carried out for a refrigeration and HVAC plant in a supermarket coupled with a Water Loop Heat Pump (WLHP) system. The water loop is used as a heat source/sink for the refrigeration unit supplying the cooling capacity required by food preservation, and for several heat pumps, which provide heating/cooling inside the supermarket building. The system is modelled in TRNSYS and the role of the water loop and its thermal inertia to provide energy flexibility is investigated. The system design and control strategy are modified in order to reduce the electricity costs in presence of demand response programs based on real-time price mechanisms.
DSM, real-time pricing, water loop, heat pump, thermal storage
This work was supported by the Italian Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) within the framework of PRIN2015 project “Clean Heating and Cooling Technologies for an Energy Efficient Smart Grid”. Coccia G. would like to express his gratitude to Eng. Enio Ciarrocchi for his useful and detailed support on water thermal storages.
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