Demand side management (DSM) can be defined as a set of measures adopted to modify customers’ energy
demand with the aim of improving the efficiency of the overall energy system. Indeed, DSM strategies can be
used to reduce customers’ demand at peak times, reduce energy consumption seasonally/yearly, change the
timing of end-use consumption from high to low-cost periods, and increase consumption during off-peak
periods. DSM strategies can be implemented by using the energy flexibility available in the final users’
applications, e.g. the thermal inertia of the building mass, the presence of additional energy storage systems
enabling load shaping or the use of control systems to turn on/off end-users’ devices when required.
Being intensive energy consumers because of a high electric energy demand (mainly for refrigeration, which
accounts for about 40 % of the yearly energy consumption), supermarkets are ideal candidates for energy use
optimizations obtained through 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 that 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.
