A Systematic Approach to Predict the Economic and Environmental Effects of the Cost-Optimal Energy Renovation of a Historic Building District on the District Heating System

Vlatko Milić,Shahnaz Amiri,Bahram Moshfegh

doi:10.3390/en13010276

Abstract

The economic and environmental performance of a district heating (DH) system is to a great extent affected by the size and dynamic behavior of the DH load. By implementing energy efficiency measures (EEMs) to increase a building’s thermal performance and by performing cost-optimal energy renovation, the operation of the DH system will be altered. This study presents a systematic approach consisting of building categorization, life cycle cost (LCC) optimization, building energy simulation and energy system optimization procedures, investigating the profitability and environmental performance of cost-optimal energy renovation of a historic building district on the DH system. The results show that the proposed approach can successfully be used to predict the economic and environmental effects of cost-optimal energy renovation of a building district on the local DH system. The results revealed that the financial gains of the district are between 186 MSEK (23%) and 218 MSEK (27%) and the financial losses for the DH system vary between 117–194 MSEK (5–8%). However, the suggested renovation measures decrease the local and global CO2 emissions by 71–75 metric ton of CO2eq./year (4%) and 3545–3727 metric ton of CO2eq./year (41–43%), respectively. Total primary energy use was decreased from 57.2 GWh/year to 52.0–52.2 GWh/year.

Highlights

Fossil fuel supply sources dominate the European building heat market, representing approximately 66% of the total end-use heat demand [1]
When analyzing the effects on the local district heating (DH) system from the energy renovation of a historic district, it is important to be aware of the time-dependent behavior of the energy systems
A larger population in Visby will most likely increase the heat load of the DH system, due to more buildings being connected to the local energy systems

Summary

Introduction

Fossil fuel supply sources dominate the European building heat market, representing approximately 66% of the total end-use heat demand [1]. The total final energy use in the residential and services sector in Sweden in 2017 was 146 TWh, according to the Swedish Energy Agency [2]. Electricity and oil represent 50% and 8% of the final energy use in the residential and services sector, respectively. Substituting oil and electricity as sources of energy for heating systems with efficient use of resources via district heating (DH) is, vital in order to achieve a sustainable energy system in the building sector. Benefits from DH include the possibility to use different fuels, using waste that would otherwise be sent to landfill, cogeneration with electricity production, energy security and high supply security

Objectives

Results

Conclusion