The future role of base-load technologies

Nuclear fission, natural gas, geothermal energy, nuclear fusion: Would these base-load technologies be expedient for the German energy system in the future? These issues were analysed by the academy initiative "Energy Systems of the Future" (ESYS).

Base-load technologies are continuously available for power generation. Due to their high investment costs, base-load power plants must be in operation almost uninterruptedly in order to be profitable. At present, nuclear power plants and lignite-fired power plants feature as typical technologies.

In the case of residual load power plants the situation is different: Although these power plants are also continuously available, they only run intermittently, for example when solar and wind energy are not supplying enough electricity. Residual load power plants entail comparatively low investment costs but high fuel costs. Hydrogen-fuelled gas turbine power plants are salient examples of low CO₂ residual load power plants.

Nuclear power plants are associated with unanswered questions revolving around costs, safety, final disposal issues and proliferation. Current new construction projects are usually significantly overrunning schedules and budgets.

Natural gas power plants with CO₂ capture could probably be realised on a large scale within the next 20 years, while building up the infrastructure for CO₂ will represent a challenge.

Geothermal energy has little potential for generating electricity in Germany – here is better suited to providing thermal energy.

Nuclear fusion is not expected to be able to make a significant contribution to the electricity supply until after the year 2045 at the earliest.

The expansion of renewables and the European electricity and hydrogen grids are expected to cover the electricity demand and most of the hydrogen demand within Europe. Nevertheless, base-load power plants could still contribute to the energy supply. The key here is a flexible hydrogen system that enables the power plants to achieve high capacity utilisation. Their electricity could be used for electrolysis in times of low demand and thereby reduce hydrogen imports. However, they hardly impact on the expansion and development requirements of the grids for electricity and hydrogen, and the switch to e-mobility and heat pumps would also have to remain unchanged. Their benefits arise primarily when they are more cost efficient than their alternatives. However, due to their long construction and utilisation periods, new base-load power plants are more of a long-term option.

The overall system costs of the transition to climate neutrality by 2045 in connection with the expansion of base-load power plants – also under optimistic assumptions – are similar to those in the reference scenario, which primarily relies on the expansion of solar and wind energy. Additional risks notable here: Increased costs and delays in the construction of base-load power plants, both due to the lower level of technological maturity of the respective technologies and the typical complexity of large-scale projects.