Switzerland must quickly and drastically reduce its energy- and mobility-related greenhouse gas (GHG) emissions. In the energy- and emission-intensive residential sector, supply-side energy and mobility asset upgrades offer large opportunities for GHG emission mitigation. Particularly, the electrification of
traditionally fossil fuel based heating and private mobility is expected to significantly reduce GHG emissions.
In order to promote this energy and mobility system transformation towards lower GHG emission levels while maintaining affordable energy prices and guaranteeing reliable energy supply, the DisCREET projects investigated how decentralized gas-based co-generation, can interact with increasing shares
of partly intermittent renewable energy technologies (RET), energy storage systems (ESS) and other energy supply assets to optimally supply load sites with the required energy to power the residential electrification.
To efficiently address this complex field of interrelated, sector-coupled objectives under various technoeconomic restrictions, the DisCREET project first and foremost developed a software tool based on the Energy Hub concept, which intends to guide and improve decision-making with regards to optimal
energy system planning by numerically describing the relevant investment and operation decisions related to technological system upgrades.
The associated optimizations are carried out from the bottom-up perspective of well-informed residential consumers, which plan to upgrade their stationary energy assets and private vehicles based on strategic investment decisions, which take total system costs and lifecycle GHG emissions as the primal performance indicators to evaluate those decisions. These decisions, which define the optimal selection of technologies from a given portfolio, their optimal installation capacities, and their optimal operational schedules, are then useful for the consumers themselves, but also other stakeholders looking to
understand the consequences of optimal consumer-based decision-making towards affordable, sustainable, and secure provision of the formers’ thermal, electrical, and mobility-related energy demands.
These consequences of local decision-making are far-reaching. Results show that electrification of the residential and mobility sector can substantially reduce its GHG (up to -70% in best case scenarios), while offering comparable (and even slightly reduced) levels of total cost via the introduction of modern centralized and decentralized supply technologies. In this regard, local heat pumps, electric cars, and decentralized photovoltaic systems are the core technologies used to enable residential decarbonization. As a result of their installation the demand for electricity from the centralized energy grids shifts from unidirectional, uniform, and moderate levels of electricity demand, to bi-directional, strongly seasonal and intermittent as well as generally increased electricity demand levels, which would overburden the current centralized electricity supply system manifold, particularly in winter, if all consumers electrified their heating and mobility systems.
Under the consideration of limited electricity availability from the centralized electricity grid in Switzerland, local electrification must find ways to provide the additional electricity demands. Since also the space for roof-top PV installation is limited and this technology provides electricity mostly in summer,
decentralized combined heat and power plants (CHPPs), operating on natural gas or biogas, can offer attractive solutions in such circumstances to ensure electricity supply. CHPPs are hence found particularly attractive, whenever its main competitor, the centralized electrical grid, is (partially) unavailable, exhibits a high carbon-content or is costly. Further, biogas-operated CHPPs are shown to significantly undercut GHG emission levels from centralized combined cycles gas turbines at acceptable total costs, when operating in conjunction with the mentioned core decentralized energy technologies. Without consideration of the limitedness of the existing centralized energy systems, CHPPs are however mainly only attractive for cost-driven energy systems, for large demand sites, and at high heating supply temperatures.
Overall, the data, the methodology, the computational model, and the results presented in work enable robust suggestions for quick, affordable, secure, and deep decarbonization of the residential energy and mobility sector via electrification.
