Residential buildings with heat pumps peak power reduction with high performance insulation

Abstract

Revised EPBD directive has set ambitious targets for nearly zero energy buildings. In residential buildings, energy performance can be improved mainly by applying better insulation of building fabric and by efficient energy sources, i.e. heat pumps. Electricity use and peak powers will increase when heat pumps, both air to water and ground source heat pumps, are used for heat source in new residential buildings compared to heating solutions that do not use electricity. The purpose of this study was to determine how much the high performance thermal insulation can compensate the increase of electricity use and peak power caused by extensive application of heat pumps in Finland residential buildings. The present study used five residential buildings that describe residential newbuild market. Finnish regulation defines minimum insulation level and high performance insulation level which were applied to single family houses, terraced house and apartment buildings to simulate electric power values all year round. Hourly electrical power values were simulated with dynamic simulation software IDA ICE. Results show that electricity use and peak powers are rising significantly when heat pumps are used, but better insulation level significantly decreases or even fully compensates the amount of additional electric power. The results can be used for the assesment of implications of extensive use of heat pumps to power grid.