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

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.

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

Marilyne Andersen, Arianna Brambilla, Endrit Hoxha, Thomas Bernard Paul Jusselme

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.

2016

On the necessity of improving the environmental impacts of furniture and appliances in net-zero energy buildings

Endrit Hoxha, Thomas Bernard Paul Jusselme

There is now clear evidence regarding the extensive use of furniture and appliances in daily human life, but there is less evidence of their impact on the environment. Responding to this gap in knowledge, this study focuses on an assessment of the environmental impacts of furniture and appliances as used in highly energy efficient buildings. Their primary energy, non-renewable energy and global warming potential indicators have been assessed by extending the boundaries of the Life Cycle Assessment (LCA) study beyond the building itself. In conclusion, we found that furniture and appliances were responsible for around 30% of greenhouse gas emissions and non-renewable energy consumption and 15% of primary energy consumption comparing to the overall impacts of the building. Since embodied impacts represent the largest values, the process for labelling the appliances' energy efficiency should encompass a life-cycle point of view, not just a usage point of view as the case currently. Among office appliances, computer equipment was ranked as the highest impacting element, especially laptops and monitors. As for domestic appliances, refrigerators and electric ovens had the biggest impacts. Concerning furniture, the greatest impacts were from office and kitchen cabinets.

Elsevier2017

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

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

Marilyne Andersen, Arianna Brambilla, Endrit Hoxha, Thomas Bernard Paul Jusselme

2016