Dynamic Life Cycle Assessment of Buildings
The Swiss Energy Strategy 2050 aims at strongly reducing the national final energy demand, especially in the building sector. However, while a reduction of the fossil fuel dependency for space heat and domestic hot water production is expected, the national electricity consumption should remain stable in the next decades. In the building sector, this situation implies an important shift from fossil fuel based heating solution to electrical solutions (mostly heat pump). In addition, decentralized electricity production systems (photovoltaic, etc.) are expected to strongly grow.
Currently, the approach to quantify the environmental impact of the building electricity demand in Switzerland relies on the Life Cycle Assessment (LCA) methodology which considers the impacts from cradle to grave. However, the current method considers that the environmental impacts of the consumed electricity are constant and calculated on a yearly basis. In addition, the building electricity demand is varying over the year, especially when the heat is provided with heat pump systems.
The Swiss electricity production scheme is highly variable over the time. It depends of the availability of the centralized electricity production means (nuclear and hydro power plants) but also to the climatic conditions that will influence the production of decentralized electricity production installations. Altogether, this implies a high variability of the Swiss electrical importation from the neighboring countries (which have also a variability over the time of their production means for the same reasons as Switzerland).
Thereby, the environmental impacts of the consumed electricity is Switzerland are variable from hours to hours over the years because of the supply and demand variability. It is thus necessary to assess the influence of this variability over the building environmental impacts, considering different time steps.
The EcoDynBat project, developed in collaboration with EMPA and SUPSI aims thus at characterizing the environmental impact of the building electricity demand by considering all these variability sources with different time steps (hour, day, week, etc.).
The project will then identify what is the most appropriate time perspective to be considered for the environmental impact assessment of the electricity building demand.