Model
Understanding how structural changes occur in energy supply requires approaches that are able to represent the structure of the energy system in detail and the main factors affecting structural change. Among these factors, system-wide effects are likely to be particularly important given that technological change in one subsector of the
Understanding how structural changes occur in energy supply requires approaches that are able to represent the structure of the energy system in detail and the main factors affecting structural change. Among these factors, system-wide effects are likely to be particularly important given that technological change in one subsector of the energy system can influence the choice of technology of other sectors, including the energy production and conversion infrastructures. The structural evolution of the energy sector is also driven strongly by energy demands, including temporal and spatial factors; emerging technologies; and linkages mediated by transmission and distribution infrastructure. Although structural change in the energy system is almost certain to occur, the direction and extent of change is affected by uncertain factors related to technology breakthroughs, policy and market developments and external factors such as fossil fuel price and the global carbon market. To account for this range of factors, we developed a technology-rich, bottom-up energy-systems model using the advanced modelling framework TIMES – the Swiss TIMES Energy system Model.
In the Swiss TIMES energy system model (STEM), the full energy system is depicted from resource supply to end-use energy service demands (ESDs), such as space heating, mechanical processes, and personal/freight transport (in vehicle- or tonne-kilometre). The model represents a broad suite of energy and emission commodities, technologies and infrastructure as illustrated in the reference energy system below. The model also combines a long time horizon (2010-2100) with an hourly representation of weekdays and weekends in three seasons. The model is used to identify the least-cost combination of technologies and fuels to meet future ESDs (which are given exogenously based on a set of scenario drivers), while fulfilling other technical, environmental and policy constraints (e.g. CO2 mitigation policy). The model outputs include technology investment and energy commodity use across all sectors, which can be aggregated to report primary energy supply and final energy consumption, seasonal/daily/hourly electricity demand and supply by technology type, carbon dioxide (CO2) emissions, cost of energy supplies, and the marginal cost of energy and emission commodities, among others.
The high level of technology detail ensures that the future energy pathways identified by the model account explicitly for the characteristics of the necessary technology options, and thus are feasible from an engineering perspective. The century long time horizon of STEM facilitates the analysis of long-term goals and challenges, and accounts for the long lifetimes of energy-related capital infrastructure. The high level of time resolution enables STEM to account for the temporal variations in supply and demand, which is critical for evaluating the deployment of intermittent renewables, electrification of transportation and heating, and an emerging need for storage and/or additional flexibility in imports and exports. STEM is thus a powerful tool for the analysis of exploratory transition scenarios of the energy system.