Germany would like to be greenhouse gas neutral as soon as 2045. For this reason, Fraunhofer ISE has completely recalculated a study with its energy system model "REMod". Four scenarios are conceivable here.
In the study »Ways to a climate-neutral energy system«, the Fraunhofer Institute for Solar Energy Systems ISE shows different ways to achieve climate neutrality. Researchers at the Institute calculated different scenarios with the energy system model »REmod«. In all scenarios, the reduction targets are still achievable by 2045, but on different paths and at different costs.
The good news: In all scenarios, the necessary transformation of the energy system is feasible from a technical and systemic perspective. However, rapid expansion is required at all levels, as well as almost exclusive investment in target-compatible technologies from now on.
The already considerable effort will be even greater if societal behaviors inhibit the transformation, because: The continued operation of conventional technologies significantly increases the additional costs. The »persistence« scenario, for example, is characterized by strong resistance to new technologies in the private sector, such as an adherence to combustion technologies for heating and mobility. In order to still be able to achieve the tightened climate targets, the import volumes of synthetic energy sources must increase to 1,000 TWh.
The »Inacceptance« scenario is characterized by strong resistance to further expansion of large infrastructures such as wind turbines, leading to high investments for photovoltaics, batteries and electrolysers.
In the »sufficiency« scenario, on the other hand, behavioral changes in large parts of society lead to a noticeable reduction in energy consumption.
The »Reference« scenario represents a comparative scenario in which the limitations or favoring assumptions of the other scenarios do not apply.
Relative to Germany's 2020 GDP, the net annual additional expenditure is sufficient. However, if the additional expenditures are set against the savings from avoided environmental damage of €2,000 billion, the net additional expenditures are reduced to between €340 billion (reference) and €1,300 billion (inacceptance), depending on the scenario.
»In the case of sufficiency, costs of up to € 1,000 billion are saved, which underlines the significant influence of societal behaviors and attitudes on the transformation of our energy system,« explains Dr. Christoph Kost, Group Leader Energy Systems and Energy Economics at Fraunhofer ISE.
The pace of CO2 emission reduction of individual sectors is strongly dependent on the scenario considered. Only the energy industry is decarbonized significantly faster than the other sectors in all scenarios.
To achieve this, installed capacity for wind energy and photovoltaics must increase to 550 to 770 GWel by 2045, five to seven times the current level. This requires a paradigm shift: from demand-driven energy supply by large power plants to a continuous balance between conditionally controllable and forecast and, as far as possible, flexible use of energy. The energy system gains flexibility, for example, by linking the sectors of energy management, buildings, industry and transport. In addition, with power-to-X technologies, battery storage and flexible power plants. It is also necessary to integrate the German power grid more strongly into the European power grid.
Likewise, electrolysis, combined with hydrogen use in transport or the chemical industry, can be a key element of energy supply. Thus, electrolyzer capacity could be between 40 and 160 GWel in 2045. In addition, the primary energy supply decreases significantly: from 3,300 TWh today to 1,850 TWh (sufficiency) to 2,450 TWh (persistence). However, every individual is challenged: Efficient energy use – for example, by environmentally conscious behavior – reduces the necessary amount of technical equipment and the costs for it.
The development of the sectors, expansion paths, electricity profiles and emissions can be traced in interactive graphics on the Fraunhofer website.
Fraunhofer ISE (Institut für Solare Energiesysteme)