The energy transition is an ambitious generational project looking to establish a greenhouse gas-neutral energy system. This requires fundamental changes to the energy system.
At the same time, energy should remain affordable for all consumers (residential, commercial and industrial customers) and supply security should be maintained at a high level. A number of political objectives have already been adopted for this transformation. Gas as an energy source will play an important role in implementing these goals.
Phase-out of coal-fired and nuclear base load generation
The withdrawal from nuclear energy was a political decision taken back in 2011 against the background of the events in Fukushima. Some power plants have already been taken off the grid. The phase-out law provides for a phased shutdown of all German nuclear power plants by the end of 2022. Electricity generation from coal (including lignite) will also be phased out because of high carbon emissions from coal-fired power plants. A commission for "Growth, Structural Change and Employment" set up by the current German government has proposed to phase out coal by 2038, and work is currently underway on the necessary legislation. The phase-out of coal and nuclear energy will eliminate two key base-load energy sources in Germany’s current electricity mix. Going forward, gas-fired power plants with a base load capability (currently around 13% of electricity generation) will therefore play an increasingly important role in securing the supply of electricity. The fossil natural gas used in these gas-fired power plants today and in the medium term can be replaced by renewable or decarbonised gases (e.g. synthetic methane) in the future and thus made climate-neutral.
Growing share of renewable electricity generation
The energy system of the future will also be characterised by strongly increasing shares of renewable electricity generation. The political goal is to grow the share of renewables from around 36 percent today to 65 percent in 2030. This requires not only more renewable generation capacity, but also a massive expansion of the electricity grids. Today, we are already seeing bottlenecks due to the poorly synchronised expansion of renewable energy generation and grid infrastructure, and these bottlenecks pose ever greater challenges to security of supply. Gas-fired power plants which can be used flexibly, especially in southern Germany, are making an important contribution to security of supply here.
By intelligently linking the power and gas infrastructures, it will be possible to compensate for bottlenecks in power grids using the well-developed and efficient gas infrastructure. Gas pipeline systems already transport almost twice as much energy as the power grids. In future, surplus electricity from renewable sources could be converted into gaseous energy using power-to-gas technologies and transported to the centres of consumption via the gas network. This could also limit the need for new electricity infrastructure (beyond the current plans as set out in the 2035 Electricity Network Development Plan). This close integration of two infrastructures would not only contribute to public acceptance of the energy transition but also make sense from an economic point of view. In this context, the gas transmission system operators (TSOs) are proposing joint, integrated Network Development Planning.
Further challenges for supply security are posed by the intermittent availability of renewable energy sources and the limited and mostly short-term storage options for electricity. Wind and solar power plants only generate energy when the wind blows and the sun shines. However, since electricity cannot be stored in sufficient quantities (electricity storage facilities in Germany have a total capacity of 0.04 TWh compared with 234 TWh for gas), these intermittent energies need to be backed up by other sources. This is where gas-fired power plants, which can be operated much more flexibly, come into play. In addition, gas infrastructure can also offer a solution to the storage problem because it is already possible to store large quantities of energy by using power-to-gas in conjunction with existing gas transmission pipelines and storage facilities. This way, electricity generated from renewable energy sources such as wind and solar can be efficiently stored and integrated into the energy system.
An almost carbon-neutral energy system
With regard to its greenhouse gas emissions, Germany has set itself reduction targets of 55 percent by 2030 and 80-95 percent by 2050. These climate targets apply not only to the energy sector, but also to the industrial, transport and building sectors. Gaseous energy sources can make a significant contribution to achieving climate targets, and renewable and decarbonised gases bring climate-neutral energy to sectors that are difficult or expensive to electrify. In the heating sector, for example, gas currently accounts for almost 50 per cent. Given the intermittent availability of renewable electricity and the high seasonality of heat demand, complete electrification of this sector would be many times more expensive and indeed unrealistic due to the lack of long-term storage options. In the transport sector, too, the use of other renewable and decarbonised gases (such as hydrogen) offers an efficient way of cutting greenhouse gas emissions, along with the energetic use of biomass. In industry, especially in high-temperature processes above 500 degrees Celsius, the use of renewable and decarbonised gases is indispensable when it comes to reducing greenhouse gas emissions.
The gas infrastructure as well as renewable and decarbonised gases will therefore play a key role in meeting climate targets. Without these gases, decarbonisation of the heating, transport and industrial sectors would not be economically efficient.