Cost-Optimal Plus Energy Building in a Cold Climate

Szymon Firląg

doi:10.3390/en12203841

Abstract

The main objective of this article is to propose possible requirements for cost-optimal plus energy building in a cold, heating dominated climate. The open question is what is more cost-effective: reduction of energy demand or increase of production from renewable energy sources. The target of the research was to check which solution has the lowest investment and maintenance costs. The analysis was made for a single-family house located in central Poland, including three different energy standards: WT2021 with energy need for heating ≤100 kWh/(m² year), NF40 with energy need for heating ≤40 kWh/(m² year) and NF15 with energy need for heating ≤15 kWh/(m² year)). Air and ground source heat pumps were used as a heat source and a photovoltaic system for the production of the electrical energy. For each case the investment and running costs were calculated very precisely, taking into account heating, ventilation, domestic hot water and auxiliary systems. Global cost for a 30-year period showed that house variants with air source heat pumps are more cost effective. The investment, replacement and maintenance cost related with energy systems have the biggest share in the global cost. Reaching the plus energy standard was possible only in the case of low-energy standard NF40 and NF15. Based on this research the proposed requirements for plus energy single-family residential buildings in central Poland are the following: the final (delivered) electrical energy demand (including heating, ventilation, domestic hot water and auxiliary systems) <45 kWh/(m² year) and the on-site electrical energy production >45 kWh/(m² year).

Highlights

IntroductionThe Energy Performance of Buildings Directive (EPBD) [1] requires that all new buildings constructed in the European Union (EU) from 2021 (in the case of public utility buildings from 2019)are buildings with nearly zero energy consumption (NZEB)
The Energy Performance of Buildings Directive (EPBD) [1] requires that all new buildings constructed in the European Union (EU) from 2021are buildings with nearly zero energy consumption (NZEB)
The global cost values obtained proved that the NF40 (41,732 EUR) and NF15 (42,048 EUR) variants using the air source heat pump were the most favourable

Summary

Introduction

The Energy Performance of Buildings Directive (EPBD) [1] requires that all new buildings constructed in the European Union (EU) from 2021 (in the case of public utility buildings from 2019)are buildings with nearly zero energy consumption (NZEB). The Member States, including Poland, have set out the country requirements for standard NZEB [3]. These requirements include, among others, thermal insulation of buildings elements and maximum non-renewable primary energy consumption (in Poland only the part of the energy that is coming from fossil fuels is included in the calculations). The study of Gustafsson [8] concentrates on building energy systems in the context of renovation. This is especially important when aiming towards the

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Conclusion