Potential of structural thermal mass for demand-side management in dwellings

In order to avoid grid instability and decreasing production efficiencies of large power plants due to a widespread integration of renewable electricity production, demand-side management (DSM) is proposed as a solution to overcome the possible mismatch between demand and supply. This research evaluates the potential to improve the balance between the electricity use for heating and local electricity production of a nearly zero energy building (nZEB), by active use of structural thermal storage capacity of the building. To quantify the DSM potential of structural thermal storage, the cover factors and peak electricity demand of a single family dwelling equipped with a photovoltaic (PV) system are chosen. Detailed representations of the PV system and the dwelling itself, heated by an air water heat pump, are implemented in the modeling environment of Modelica and simulated for the heating-dominated climate of Belgium. The influence of the insulation level and the embedded thermal mass of the construction on the DSM potential is evaluated. The impact of the heat emission system is estimated by comparing a floor heating system with a radiator emission system. Results show that although the influence on the cover factors is limited, the use of the structural storage capacity for demand-side management shows strong potential to shift the peak electricity use for heating to off-peak hours. Furthermore, it is shown that not only the availability of the thermal mass, but also the interaction between the heating system and the thermal mass is of significant importance. (C) 2013 Elsevier Ltd. All rights reserved.