Scientific academies demand a rethink: Climate targets can only be achieved through cross-sectoral solutions

14. November 2017

Too many fossil fuels, too little advancement: Germany will fall noticeably short of its climate targets if we stay on the same track. Only with an explicit strategic change to more coupling of the sectors can targets be achieved over the long-term, according to the Academies’ Project “Energy Systems of the Future” (ESYS). In the position paper published today “Coupling the different energy sectors” – Options for the next phase of the energy transition, acatech, Leopoldina and the Union of German Academies are demanding a more robust interlinking of the electricity, heat and transport sectors and the integration of more renewables into the system. As a central regulatory element, they are speaking out in favour of a unified CO2 price.

The energy transition is in a rut. Even though wind power and photovoltaics have been expanded considerably in recent years, the energy supply in Germany is still based on fossil fuels – at around 80 percent. Only through a considerable expansion of renewables and through a cross-sectoral, effective CO2 price can the energy supply become environmentally friendly, safe and affordable over the long term. This has been shown by acatech – the German Academy of Science and Engineering, the National Academy of Sciences Leopoldina and the Union of German Academies of Science in their position paper. “The energy transition is now entering into a new phase”, explains Eberhard Umbach, acatech presidium member and co-director of the respective ESYS working group. “Up until now, the production of electricity has been in the spotlight. So that fossil fuels can for the most part be driven out of the energy system by 2050, we have to tackle the energy supply in a cross-sectoral manner. With efficient wind power and photovoltaic plants as well as innovative technologies for energy consumption, we now have the appropriate tools at our disposal. The new government has to establish parameters for coupling the sectors in Germany in a timely manner”.



Based on expert discussions, a comparison of relevant energy scenarios and their own model calculations, the scientists of the Academies’ Project have identified trends for the future energy supply, thereby identifying options for Germany. The position paper shows: electricity from renewable sources will become the prevailing energy source – even in transport and heat supply. “Technologies such as electric vehicles and heat pumps, which use electricity directly and efficiently, will become increasingly important in the future. We have to begin to more forcefully introduce them into the market. So that the system remains secure in terms of long-term supply, it should be complemented by hydrogen and synthetic combustibles and fuels for sea and air transport, for example, as well as compensate for seasonal weather bottlenecks”, says Hans-Martin Henning. The director of the Fraunhofer Institute for Solar Energy Systems ISE led the working group together with Eberhard Umbach.

Energy systems without fossil-fuel energy sources

Through new applications in the heat and transport sectors, electricity consumption could almost double by 2050. This would lead to increased demand within the energy system:

  • Capacities in wind power and photovoltaic plants compared to today’s output would have to increase five to seven-fold. Measures for the efficient use of energy could help to contain this expansion and safeguard the societal acceptance of the energy transition.
  • Short- and long-term storage as well as flexible power consumption models must compensate for the fluctuating power production of wind and solar. In addition to pumped storage and batteries, flexible electrolysis facilities for the production of hydrogen and methane will become increasingly important. The existing natural gas grid with its respective cavern and pore storage facilities could thus be used as long-term storage.
  • In order to safeguard the supply in all weather conditions and all seasons, reserve capacities are needed. Their scope corresponds to that of today’s conventional power plant complex. Low emission gas-fired plants, cogeneration plants that are run on hydrogen, natural gas or synthetic methane, or fuel cells are suitable for this purpose.

Costs and regulatory elements

A sustainable and secure energy supply costs money. The ESYS experts estimate that the annual additional costs for the energy transition over the next three decades will amount to between 30 and 60 billion euros on average – or higher in the worst-case scenario. This corresponds to one to two percent of today’s German gross national product. Through intelligent framework conditions, unnecessary additional costs can, however, be avoided. “We need a unified, effective CO2 price for all emissions”, explains Karen Pittel, Director of the ifo Centre for Energy, Climate and Resources and a member of the EYS working group. “Only then can electricity that is produced renewably also assert itself on the market against fossil fuels, and environmentally-friendly technologies can establish themselves”. The Academies’ Project therefore proposes that the European Emissions Trading System should be expanded to all sectors and that a price corridor should be determined. If this is unsuccessful, a European-wide or national CO2 tax could be introduced. Through these measures, the development of CO2 prices would be easier to plan and would provide companies with dependable incentives to invest in environmentally-friendly technologies. At the same time, the existing system of previous fees, levies and taxes should be reformed and streamlined. A unified CO2 price cannot, however, serve as a panacea. Supportive measures are necessary in order to overcome obstacles. This includes research and development funding as well as market incentive programmes, tax breaks or proper guidelines that, of course, should be continuously evaluated.

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