Impuls-urbs: Integration of life cycle assessment into energy system models

Achieving the goal of zero emissions will require changes to current production systems, especially in the energy sector. In order to design and implement policies to face this challenge, it will be necessary to gain an understanding of the energy systems and to assess the outputs of different scenarios. Most of the current energy system models offer limited assistance because they take only the operation phase emissions into account and neglect the upstream processes, which require large amounts of energy and add more emissions to the system. This work presents Impuls-urbs, a new model framework based on the urbs model, which integrates a Life Cycle Assessment (LCA) perspective into energy system models by adding a particularly essential life cycle stage of energy technology: that of material production. Both Impuls-urbs and urbs are applied to a simple illustrative example in order to better understand the implications of the new approach. Three scenarios are analyzed: (i) cost minimization, (ii) cost minimization with CO2 limits, and (iii) CO2 minimization. The results demonstrate that the differences between the two models become greater as CO2 emissions become more restrictive. Impuls-urbs generally provides solutions featuring lower installed capacity and lower electricity production, although the total system emissions and cost are higher than in the urbs case. The most divergent results occur in scenario (iii), in which the dominant technology in Impuls-urbs is wind, since it requires less energy and generates fewer emissions during its fabrication, whereas urbs relies on photovoltaics (PV) as the main technology.