LCA as key factor for implementation of inertia in a low carbon performance driven design: the case of the smart living building in Fribourg, Switzerland

The building sector is known as a major contributor to greenhouse gas (GHG) emissions and energy consumption. These impacts are commonly evaluated by life cycle assessment (LCA), which assess the potential impacts of a building from the construction to the end of life. LCA considers: the operating impacts (OI) occurring during the service life of buildings, and the embodied impacts (EI) occurring during the other lifecycle. Materials usually increase EI, but some of them, such the ones used for thermal inertia (TI), concur to energy efficiency and can reduce OI. This makes it difficult to understand the role of such materials in low carbon building strategies. The aim of this study is to understand how to weigh the overall environmental benefits of TI. Four building models were used to assess LCA with either low, medium, high or very high levels of TI. These are reached using materials characterized by different embodied impacts, such as concrete and earth. The difference with the low inertia case, taken as the base case, is evaluated for each model regarding OI and EI. The comparison between OI and EI determines which scenario brings the lowest impacts on LCA. To evaluate how the results are influenced by climate change, the analysis is made with two different scenarios: one with the typical meteorological year (TMY, Meteonorm) and the other with the weather conditions for 2050 (IPCC, International Panel on Climate Change). The paper shows a methodology to evaluate the effects of a design strategy on the LCA, applied to the case of TI. It demonstrates that TI is not very relevant in the frame of this case study because the EI related to the added materials is higher than the induced operating savings. Furthermore, it has been demonstrate that in the future when the carbon content of the energy may be lower, TI can change its effects and influence negatively the lifecycle environmental impacts.

Reducing Greenhouse Gas emissions is not the only solution

Justine Brun

With the increasing strength and frequency of climate change events, the urgency to mitigate climate change impact is ever so important. Canada reported his Nationally Determined Contribution (NDC) and submitted its ambition to reduce his Greenhouse Gas (GHG) emissions by 40-45% by 2030 compared to 2005 and reach net-zero emissions by 2050. Interest for energy system modelling has been increasing for planning future energy systems, as a result of growing concern for sustainable development and transition towards renewable energies. Nevertheless, planning a decarbonization of energy system can potentially lead to environmental burden shifting, and can increase impacts on other environmental impacts such as ecosystem quality or human health. Thus, this project aims towards integrating Life Cycle Analysis (LCA) and more specifically Life Cycle Impact Assessment (LCIA) within Energy Systems Modelling, in order to minimize not only climate change impacts, but human health and ecosystem quality. In addition, a dual spatial resolution was integrated in the model in order to increase data precision and computational efficiency. The results show that a low-carbon energy system, based on the optimization of GHG emissions allows to greatly reduce all the environmental impacts under analysis, compared to an all economic- based energy system, but a multi-objective optimization allows to simultaneously reduce impacts on ecosystem quality and human health, while reducing GHG emissions and keeping good economical and technical performances. The results also show that it is theoretically possible for Canada to keep on track with their emission reduction ambition by 2030, by deploying more renewable energies. This project does not allow assessing Canada’s potential to reach net-zero emissions, as environmental impacts from carbon capture technologies are still to be characterized and integrated in the model.

2022

Neutral global warming potential target of electricity storage as threshold for greenhouse gas emission mitigation in buildings

Thomas Bernard Paul Jusselme, Didier Albert Simon Vuarnoz

Coupling photovoltaic (PV) systems with energy storage (ES) in buildings, enables to increase the building’s energy autonomy and the self-consumption of onsite renewables. ES increases nonetheless the life cycle environmental impact of the stored energy. As such, there exists a threshold where the GHG emission benefits of using ES start to compensate its own embedded and operational impact. In this study, a methodology to assess this neutral global warming potential target of ES is proposed, and is extended to the primary energy and its non-renewable part. The methodology is tested on a case study consisting of a feasibility project of a building located in Switzerland. When the surplus of renewable energy that cannot be used or stored directly is exportable to the grid, the operational benefits of the ES cannot balance anymore its embedded impact. In regards to market products, these neutral targets are tighter for GHG emissions than energy. Neutral targets are greatly affected by the characteristics of the grid mix supplying the building so the use of energy storage for the mitigation of GHG emissions in buildings may be efficient in Germany, but might be technologically more challenging with low-carbon French electricity.

2018

Worldwide impacts of climate change on energy for heating and cooling

Frédéric Louis François Babonneau, Santosh Ram Joshi, Marc Vielle

The energy sector is not only a major contributor to greenhouse gases, it is also vulnerable to climate change and will have to adapt to future climate conditions. The objective of this study is to analyze the impacts of changes in future temperatures on the heating and cooling services of buildings and the resulting energy and macro-economic effects at global and regional levels. For this purpose, the techno-economic TIMES-WORLD and the general equilibrium GEMINI-E3 models are coupled with a climate model, PLASIM-ENTS. The key results are as follows. At the global level, the climate feedback induced by adaptation of the energy system to heating and cooling is found to be insignicant, partly because heating and cooling-induced changes compensate and partly because they represent a limited share of total nal energy consumption. However, signicant changes are observed at regional levels, more particularly in terms of additional power capacity required to satisfy additional cooling services, resulting in increases in electricity prices. In terms of macro-economic impacts, welfare gains and losses are associated more with changes in energy exports and imports than with changes in energy consumption for heating and cooling. The rebound eect appears to be non-negligible. To conclude, the coupling of models of dierent nature was successful and showed that the energy and economic impacts of climate change on heating and cooling remain small at the global level, but changes in energy needs will be visible at more local scale.

Springer Verlag2015