Environmental Payback of Renovation Strategies in a Northern Climate—the Impact of Nuclear Power and Fossil Fuels in the Electricity Supply

Abstract

The aim of this study is to assess how the use of fossil and nuclear power in different renovation scenarios affects the environmental impacts of a multi-family dwelling in Sweden, and how changes in the electricity production with different energy carriers affect the environmental impact. In line with the Paris Agreement, the European Union has set an agenda to reduce greenhouse gas emissions by means of energy efficiency in buildings. It is estimated that by the year 2050, 80% of Europe’s population will be living in buildings that already exist. This means it is important for the European Union to renovate buildings to improve energy efficiency. In this study, eight renovation scenarios, using six different Northern European electricity mixes, were analyzed using the standard of the European Committee for Standardization for life cycle assessment of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation, and improvement of the building envelope. The results show that while in some electricity mixes a reduction in the global warming potential can be achieved, it can be at the expense of an increase in radioactive waste production, and, in mixes with a high share of fossil fuels, the global warming potential of the scenarios increases with time, compared with that of the original building. It also shows that in most electricity mixes, scenarios that reduce the active heat demand of the building end up in reducing both the global warming potential and radioactive waste, making them less sensitive to changes in the energy system.

Greenhouse Gas Payback Time of Different HVAC Systems in the Renovation of Nordic District-Heated Multifamily Buildings Considering Future Energy Production Scenarios

“…The emission factor for the Nordic mix is currently around 90 g/kWh [62], whereas in the EU, the emission factor for electricity was 334 g/kWh in 2019 [68]. Utilizing this factor in the life cycle assessment can significantly impact this study's results, as demonstrated in a former study conducted by Ramirez [40]. It is important to emphasize that, both today and in all future electricity scenarios, Sweden is a net exporter of electricity [43].…”

“…To offer insights into the environmental impact of building materials, the software incorporates predictions of CO 2 e emissions using EPD datasets available within the tool. One Click LCA has been employed in various studies to evaluate the environmental impact of diverse projects [40,41,[53][54][55].…”

“…Life cycle analysis (LCA) has played a central role in various studies concerning the renovation of residential buildings [28,30,[34][35][36][37][38]. In the case of the renovation project under analysis in this study, researchers closely followed the project from its beginning, employing different assessments to select renovation measures through simulation software [39][40][41][42]. This research, part of the project's evaluation process, offers a real assessment of the chosen renovation scenarios.…”

The greenhouse gas emissions of nuclear energy – Life cycle assessment of a European pressurised reactor

“…cradle to grave) GHG emissions of HPC, using the three main LCA methods and publicly available information that is relevant to the plant or the wider context. In addition to the contribution that our work makes to the literature on nuclear energy, it is useful to note that the carbon-intensity of nuclear energy, is also used as input data in other studies, for instance in investigating future scenarios for building renovations [12], thus enhancing the importance of reliable and accurate numbers.…”

Clean Energy Solutions and Sustainable Development

“…Nevertheless, the projected spike in supply and use of energy presents a serious challenge for the global community regarding the sustainability of our energy system (Khaled et al 2017;Blomqvist et al 2019). This makes it imperative to modify the supply and use patterns, to avert irreversibly harmful effects on the climate and environment (Ramírez-Villegas et al 2020). There are several possibilities to realizing such an objective.…”