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Research
Climate neutrality clearly calculated
In order to achieve its climate protection targets by 2050, Germany must comprehensively restructure its energy system. How can this be realised at the lowest possible cost? Moreover, will the government’s current climate protection package achieve this goal? Jülich scientists have developed a whole range of computer models to answer these questions.
The task
Using computer models, researchers from the Institute of Energy and Climate Research (IEK-3) simulated the reorganisation of the German energy system. Their goal was to calculate the economically most advantageous road up to the year 2050 step by step, starting from the current situation. In the study, they had considered two different emission targets: a 95 per cent reduction in greenhouse gases and an 80 per cent reduction. Only the 95 per cent scenario corresponds approximately to the climate neutrality that the EU is striving for, so it is the results of these calculations that will be presented below.
The assumptions
- The German economy will grow continuously by 1.2 per cent per year until 2050.
- The number of inhabitants in Germany will decrease slightly to 76.6 million. Nevertheless, the number of households will rise due to the continuous trend towards smaller households.
- In accordance with the recommendations of the national commission on coal, Germany will phase out the generation of electricity from coal by 2038.
- Germany will phase out nuclear energy by 2022.
- Until 2030, the electricity grids will be expanded according to the plans of the Federal Network Agency.
- No carbon dioxide (CO2) will be stored in underground deposits.
Energy balance in 2050 with a 95 per cent reduction in greenhouse gas emissions. Primary energy consumption is the required amount of energy that is available from naturally occurring energy sources and energy imports. It is supplied to the end user via various energy carriers.
“There is no doubt that the energy transition will continue to involve high investments for a long time to come. However, the transformation costs are predictable and manageable, while subsequent adaptation costs to climate change are uncertain and are likely to be several times higher.”
Martin Robinius, head of the study
Major results
EXPECTED COSTS
The most cost-effective way to achieve a 95 per cent reduction in German CO2 emissions by 2050 will cost Germany a total of € 1,850 billion over a period of 30 years. In the process, annual costs will rise from around € 9 billion in 2030 to € 71 billion in 2040 and € 128 billion in 2050. These are undoubtedly substantial amounts. However, the economic burden is not as high as one might expect, but is in the ballpark of today’s expenditure on energy supply. In 2018, Germany spent € 63 billion on energy imports, which was equivalent to 1.9 per cent of gross domestic product. The € 128 billion in 2050 would correspond to 2.8 per cent of the expected gross domestic product.
ENERGY CONSUMPTION
Electricity consumption will remain almost constant until 2035 compared to today, but will then increase by 80 per cent until 2050. This is because, in order to reduce CO2 emissions, fossil fuels are being replaced. This can be achieved with technologies that require electricity: for example, with electric heat pumps for space heating instead of oil and gas heating, or with Power-to-X technologies that produce hydrogen, for example with electricity from renewable energies – an energy carrier that will be needed in the future.
ENERGY SOURCES
The backbone of future power generation will be wind power and photovoltaics. In 2050, German plants will each produce almost six times the amount of electricity they generate today. This means that Germany will have to build additional wind turbines with a capacity of 6.6 gigawatts and solar plants with 3.9 gigawatts every year until then. This is many times higher than the current expansion rates.
Biomass and biogas will cover a quarter of Germany’s energy requirement in 2050, mainly supplying heat for buildings and industrial processes.
Dependence on energy imports will decrease considerably: while around 70 per cent of energy is imported today, the share will be 20 per cent in 2050.
ENERGY EFFICIENCY
In order to reduce CO2 emissions, it is essential to use energy more efficiently in all consumption sectors – buildings, transport, industry. Since electricity generation will still involve considerable CO2 emissions until 2035, it is particularly effective to take immediate energy-saving measures. For example, until 2035, Germany must double the previous speed of energy-efficient renovation of its existing buildings. Heat pumps will become the most important heating technology by 2050.
Development of net electricity consumption by 2050
Gross electricity generation and share of renewable energies by 2050
ENERGY STORAGE
In order for Germany to have enough energy even during a so-called “cold Dunkelflaute” lasting for days – dark doldrums with high heating demand, no sun and no wind – it needs huge energy storage facilities. Underground cavities are suitable for this purpose, such as those in salt domes, in which hydrogen is stored and extracted. Underground gas storage facilities can also be converted for this purpose. Storage power plants, in which air is pumped into a cavity and compressed, have proven to be the cheapest way to react quickly to shorter fluctuations in energy production or consumption. When electricity is required, this air is used to drive turbines.
In 2050, almost 12 million tonnes of hydrogen will be needed annually. Half of this will come from domestic electrolysis production; foreign electrolysis sites sell Germany the other half. In order to transport and distribute hydrogen in Germany cost-efficiently, pipelines need to be constructed.
Hydrogen demand for sector coupling by 2050
The computer models
About a dozen scientists from the Jülich Institute of Energy and Climate Research (IEK-3) have designed a novel range of computer models. All modules from this range can be combined and are characterised by an exceptionally high level of temporal and spatial detail: for example, one of the models can analyse and predict how much renewable energy is available in Europe for each hour and for each longitude and latitude.
It accesses weather data from the past 37 years and takes into account, among other things, the regulations for the construction of new photovoltaic or wind power plants, such as their minimum distances from buildings. Another model maps the European extra-high voltage and high voltage grid on the basis of existing expansion plans, thus providing essential information on possible imports and exports of electricity.
The scientists have fed the data from all individual models into the central component of the model range, NESTOR (National Energy System Model with integrated SecTOR coupling). NESTOR maps the entire German energy supply across all consumption sectors, including costs, from the source of energy via all conceivable paths to the energy ultimately used. On the road to 2050 and the 95 per cent reduction target, NESTOR is looking for the technologically and economically best energy system for every moment. A new method also allows the uncertainty of future costs to be taken into account.
Further information about the study can be found at fz-juelich.de
Frank Frick
Photos: Forschungszentrum Jülich
