Actual impact of heat pumps to energy performance of apartment buildings in Estonia

Abstract

As buildings consume about 40% of final energy in Europe it is seen as a most promising field for savings. EU has come up with Clean Energy Package in 2017, part of which is energy in buildings. Thus, member states are tightening their building energy consumption regulations. Under Estonian regulation of energy performance in buildings, heat pumps have been preferred over district heating for heat supply. According to a building model, the regulation is based on, those would reduce overall energy consumption and deliver significantly lower energy performance values. This study main aim is to check those assumptions used based on actual metered energy consumption data of apartment buildings recently renovated with on-site heat pumps. During the analysis it has been found out that insulation of buildings reduces heat consumption in average by 22% compared to the situation before renovation. However, heat purchase from DH network drops in average by 69% as on-site heat pump produces 61% of reduced heat demand from purchased power. Even considering additional power used in heat pump with its weight factor, energy performance of buildings is improved significantly. However, carbon footprint of buildings rises as power generation in Estonia is dominated by fossil fuels while district heating has over 50% share of renewables. Risk of increased carbon emissions is clearly not the intention of the regulation. To correct that misbehaviour, the regulation was updated in 2019. Analysis of the update shows that it does not fully rectify the situation as there are still 25% of cases when heat pumps still post better energy performance than renewable DH.