1 Background
According to the Intergovernmental Panel on Climate Change (2022), human activities are the main causes of climate change, particularly the burning of fossil fuels in the energy systems. “Global greenhouse gas emissions have continued to increase, with unequal historical and ongoing contributions arising from unsustainable energy use, land use and land-use change, lifestyles and patterns of consumption and production across regions, between and within countries, and among individuals” (Intergovernmental Panel on Climate Change 2022, 4). The increase in greenhouse gas emissions is leading to rising global temperatures, to more frequent extreme weather events and to other environmental impacts. To mitigate these effects, political decisions can play a crucial role in climate change by creating policies, regulations and incentives to reach a more sustainable energy systems which is the source of three-quarters of the global greenhouse gas emissions (International Energy Agency 2021). The Federal Council declared on 28th August 2019 that Switzerland will limit its greenhouse gas emissions to what can be naturally or technically absorbed by 2050. This target aims to reduce net emissions to zero and contribute to the global effort to limit global warming to below 1.5 degrees Celsius (Swiss Federal Council 2020).
The key to reducing carbon dioxide emissions is a good urban energy planning. Energy planning allows for the development of a long-term strategy with the establishment of rules to provide energy to all inhabitants of a city or region. Urban energy planning takes into account different factors such as energy demand, energy production, infrastructure, environmental impacts and socio-economic aspects. To reduce the environmental impact of the urban energy system, some strategies can be implemented such as electrification of the energy system, renovation of building insulation and the establishment of energy communities.
The electrification of the energy system allows a transformation of the energy system and will lead from fossil fuels to renewable energies. The electrification leads mainly to the deployment of electric alternatives like solar photovoltaic panel (PV), heat pumps (HP) and electric vehicles (EV). Moreover, the global share of electricity in final energy use is projected to increase to 50% by 2050 compared with 20% in 2018 (International Renewable Energy Agency 2019). Renovation of building insulation lead to energy saving and thus to a reduction of greenhouse gas emissions. In addition, investment in renovation of buildings insulation allows owners and tenants to reduce their electricity bills and benefit from long-term savings. It also increases the comfort of the inhabitants in summer and winter. To achieve the EU’s energy efficiency and \(CO_2\) reduction targets, the European commission has identified building insulation as a key strategy. The concept of energy communities refers to a group of individuals, households, or organizations that collaborate to collectively manage to optimize their energy resources. The goal is to accelerate the adoption of renewable energy and support sustainable development not only by fostering a sense of ownership, but also by sharing responsibility (Soeiro and Dias 2020). Therefore, it is seen as a potential solution to the different problems mentioned before.
These strategies are global and must be optimised to maximise the performance of the system. Moreover, in urban energy planning, strategies related to energy demand and production can be approached from different scales, namely at the individual building level or at the district level. With the first approach, optimisation is carried out on each building individually, whereas with the second approach, optimisation is carried out at the level of a predefined group of buildings. This optimisation at district level is in line with the concept of energy communities mentioned earlier.
This paper concentrates on analysing energy demand within the context of district-level planning. In order to begin, we provide an overview of the existing research methodology for energy optimization in urban planning, as well as of the use of energy communities. We also define relevant concept for our work. Then, we present our research question as well as the questions underlying it. Following this, we successively develop our working methodology in detail before talking about our case study and presenting the results.