© Research Centre Jülich

Solutions for greenhouse gas neutrality

Flood disasters in Germany, devastating forest fires in California, droughts and floods: The stricter climate protection law, which was sued before the Federal Constitutional Court and came into force in August of this year, is certainly not coming too soon. “Net zero” is the goal. Germany is committed to becoming greenhouse gas neutral by 2045. Emissions are to be reduced by 65 percent by 2030 compared to 1990. Is that still feasible? And how much is it going to cost? Jülich systems researchers have analysed what is needed to achieve these ambitious goals – and to do so as cost-effectively as possible.

The analyses of the Jülich systems researchers show that it is possible to achieve greenhouse gas neutrality by 2045, both technically and economically. But it won’t be easy. “Compared to the previous reduction targets, the new targets of the Climate Protection Act represent a turning point,” explains Prof. Detlef Stolten, Director of the Jülich Institute for Techno-Economic Systems Analysis. “They require a dynamic of change that is fundamentally different from the development of the past years. What is needed is the immediate introduction of measures in all sectors.”

The Jülich systems researchers have spent months calculating and modelling with computer models specially created for this purpose to find out what the solutions and paths to greenhouse gas neutrality might look like. In their study, they present a scientifically sound analysis of the necessary measures and strategies, generation paths and interactions – down to the last detail: from regional wind power and photovoltaic expansion possibilities to future international import and export networks.

The cornerstones: electricity and hydrogen from renewable energies

Fossil energy sources, the modelling shows, must be replaced as far and as fast as possible. As a result, electricity consumption will increase significantly in the future – in all sectors. Therefore, the conversion of the German electricity supply to CO2-free producers is one of the basic prerequisites for achieving net zero. “This requires a massive expansion of renewable energies,” explains Stolten. “Today’s onshore wind power capacity needs to be quadrupled. Compared to today, future plants will be larger, so the total number needed for this only needs to be increased slightly. Photovoltaic installations would need to be expanded on a large scale – compared to the average expansion rate over the last ten years, annual expansion rates here would need to increase by more than a factor of four. We can show that there is sufficient potential in Germany for the required expansion of wind power and photovoltaics.”

Hydrogen is a central element on the way to greenhouse gas neutrality. It is intended to replace fossil fuels on a large scale, serve as a storage facility for renewable energies, enable mobility and link the various energy sectors with each other. While its use is one option among many in some sectors, it is mandatory in some areas of industry. This applies in particular to steel production and the chemical industry, which together are currently responsible for over 40 percent of industrial CO2 emissions.

Energy saving and CO2 storage

Saving energy in all sectors is another building block on the road to greenhouse gas neutrality. The models developed by the Jülich scientists show that final energy consumption can be reduced by just under a third through measures such as insulation, heat pumps or more efficient household appliances.
Simply reducing additional greenhouse gas emissions is no longer enough. Residual emissions will still remain until 2045, mainly from industry and agriculture. “To achieve net zero, these residual emissions must be compensated by removing carbon from the natural cycle. This requires that around 50 to 90 million tonnes of CO2 be permanently stored each year, for example in suitable geological formations,” explains Peter Markewitz, co-author of the study.

Reduced dependence on energy imports

The restructuring of the energy supply will reduce energy consumption by around 40 percent by 2045. This will also reduce energy imports, from about 74 percent today to about 22 percent in 2045. In addition to the economic advantage, there is a geopolitical plus point: dependence on future energy importing countries is reduced, as are the price risks of international energy markets.

The transformation of the entire energy system poses enormous challenges in almost all areas. The Jülich researchers show that there are solutions to this problem. The annual additional costs in 2045 will amount to about 139 billion euros. “These are obviously notable additional costs,” Detlef Stolten said. “However, they are both predictable and manageable, as well as financially viable. Subsequent adaptation costs to climate change are likely to be many times higher.”

Further information:

Overview of the main findings of the study:
On the IEK-3 website (right column under downloads)