Shaping tomorrow's energy system

Green hydrogen is a climate-neutral energy source and a crucial component of the energy transition. To produce it, you need renewable electricity and water, which is broken down into its elemental components, oxygen (O2) and hydrogen (H2), by means of electrolysis. This process is also called power-to-gas. Photovoltaic systems and wind farms on land (onshore) or at sea (offshore) can be used as power sources.
Hydrogen can thus be produced wherever water and renewable electricity are available. Wind and solar energy, which are highly dependent on the weather and are not continuously available, can be stored in the gas grid in the long term and used as needed. Fluctuations or overloads in the electricity grid, for example in windy or sunny periods, can thus be effectively compensated for. The power-to-gas process makes it possible to decouple the production and use of renewable energies in terms of location and time. The production of hydrogen using electrolysis ensures that every kilowatt hour of green electricity can actually be used and that renewable energy plants do not have to be shut down when the electricity supply exceeds demand.
 

To date, the steam methane reforming process has been the main method used to produce hydrogen. This involves extracting so-called grey hydrogen from fossil fuels such as crude oil or natural gas. The gas or oil is converted into hydrogen (H2) and carbon dioxide (CO2) under the influence of steam and heat. However, the CO2 produced in this process is released unhindered into the atmosphere.
This can be avoided by directly capturing the CO2 produced during steam reforming and storing it permanently, e.g. in depleted natural gas reservoirs. This is referred to as carbon capture and storage (CCS). In addition to storage, there is also the option of using the CO2, for example in the production of plastic. This process is referred to as carbon capture and utilisation (CCU).
In both processes, the greenhouse gas does not enter the atmosphere and CO2 emissions can be reduced quickly and effectively. This is referred to as blue hydrogen.

In the pyrolysis process, natural gas (CH4) is broken down into hydrogen (H2) and solid carbon (C) by very high temperatures and the exclusion of oxygen. Since no combustion takes place, no climate-damaging CO2 emissions are produced and the two resulting products can be used in a variety of ways. The climate-neutral hydrogen, also known as turquoise hydrogen, can be fed into the gas grid and thus makes an important contribution to the decarbonisation of the energy supply. The solid carbon – also known as graphite – can be stored or used as an important raw material in numerous industrial sectors, e.g. in steel production, in battery manufacturing or in the semiconductor and solar industry.

If biogas or biomethane is used for the pyrolysis instead of natural gas, the process can not only be used to produce climate-neutral hydrogen, but also to create a CO2 sink. This is because the carbon contained in the biomethane was previously absorbed from the atmosphere by plants through photosynthesis. During the pyrolysis, this carbon is separated and thus permanently removed from the atmosphere. You can find detailed information on current research projects in a brochure on pyrolysis.

In order to meet the demand for hydrogen, a variety of production methods will need to be used. Natural gas, mainly from Norway, is used to produce blue (steam reforming + CCU/CCS) or turquoise (pyrolysis) hydrogen, which arrives in Germany via kilometre-long pipelines through the North Sea. Blue hydrogen will play a role during the transformation phase towards climate neutrality in Germany. Gradually, green and turquoise hydrogen in particular will come into use.

Normally, natural gas is transported to Germany in a gaseous state via gas pipelines from Norway, the Netherlands or Belgium, for example. However, if it is imported from countries such as the USA or Qatar, the natural gas is shipped in the form of LNG (Liquified Natural Gas) by large LNG tankers (LNG carriers) across the sea. LNG stands for Liquified Natural Gas. In the country of origin, the natural gas is first liquefied by cooling it to -161°C or, alternatively, by applying higher pressure (8 bar) at ambient temperature. This liquefaction takes place in order to be able to transport more energy in the storage tanks of the ships.
LNG terminals on the coasts in Germany are used to unload the incoming LNG tankers and to convert the LNG back into its gaseous aggregate state by means of a regasification plant so that it can be fed into the gas grid. Newly constructed LNG terminals are suitable for importing hydrogen.

Importing hydrogen

Germany is an energy importing country. It currently imports around 80% of its primary energy, mainly fossil fuels (e.g. natural gas, lignite, crude oil), from other countries. In the future, Germany will continue to rely on imports. However, in view of the energy transition and climate protection, the goal is to replace fossil fuels with hydrogen produced in a climate-neutral way. Some of this can be produced locally using electrolysis or pyrolysis, with zero emissions.

However, since there is insufficient capacity for the use of renewable energies in Germany, the majority of hydrogen will be imported from countries such as Norway and Spain, but also from non-European countries such as the MENA region, Canada or even Australia, to meet demand in Germany. For transport by sea or over long distances, hydrogen must be liquefied. This is similar to the transport of natural gas in liquefied form, but at minus 253 °C, even lower temperatures than for LNG are required for hydrogen to become liquid.

An alternative for hydrogen transport is the conversion into ammonia (NH3) using the Haber-Bosch process, which is much easier to transport. This is because the odour-intensive gas becomes liquid at minus 33°C. After transport, ammonia can be broken down into its components at high temperatures, and hydrogen is obtained again.
Here you will find more information about hydrogen import.

Normally, natural gas is transported to Germany in a gaseous state via gas pipelines from Norway, the Netherlands or Belgium, for example. However, if it is imported from countries such as the USA or Qatar, the natural gas is shipped in the form of LNG (Liquified Natural Gas) by large LNG tankers (LNG carriers) across the sea. LNG stands for Liquified Natural Gas. In the country of origin, the natural gas is first liquefied by cooling it to -161°C or, alternatively, by applying higher pressure (8 bar) at ambient temperature. This liquefaction takes place in order to be able to transport more energy in the storage tanks of the ships.
LNG terminals on the coasts in Germany are used to unload the incoming LNG tankers and to convert the LNG back into its gaseous aggregate state by means of a regasification plant so that it can be fed into the gas grid. Newly constructed LNG terminals are suitable for importing hydrogen.

Importing hydrogen

Germany is an energy importing country. It currently imports around 80% of its primary energy, mainly fossil fuels (e.g. natural gas, lignite, crude oil), from other countries. In the future, Germany will continue to rely on imports. However, in view of the energy transition and climate protection, the goal is to replace fossil fuels with hydrogen produced in a climate-neutral way. Some of this can be produced locally using electrolysis or pyrolysis, with zero emissions.

However, since there is insufficient capacity for the use of renewable energies in Germany, the majority of hydrogen will be imported from countries such as Norway and Spain, but also from non-European countries such as the MENA region, Canada or even Australia, to meet demand in Germany. For transport by sea or over long distances, hydrogen must be liquefied. This is similar to the transport of natural gas in liquefied form, but at minus 253 °C, even lower temperatures than for LNG are required for hydrogen to become liquid.

An alternative for hydrogen transport is the conversion into ammonia (NH3) using the Haber-Bosch process, which is much easier to transport. This is because the odour-intensive gas becomes liquid at minus 33°C. After transport, ammonia can be broken down into its components at high temperatures, and hydrogen is obtained again.
Here you will find more information about hydrogen import.

When producing hydrogen, biogas from biomass can be used instead of natural gas from fossil sources. If biogas is used, the effect is similar: in both steam reforming with CCU/CCS and pyrolysis, CO₂ is captured from the atmosphere, creating a CO₂ sink. In this case, the CO₂ balance of hydrogen production is negative. How deep this sink is depends on the starting material.

The use of biogas from plant residues offers a major advantage: the CO₂ contained in the biogas was previously removed from the air by photosynthesis of the plants and is separated and stored during steam reforming with CCU/CCS or pyrolysis. In turn, the production of H₂ with biogas from liquid manure makes it possible to reduce GHG emissions from animal husbandry. This supports the agricultural sector in reducing emissions while generating additional energy. Furthermore, the CO₂ contained in the biogas does not enter the atmosphere.

The potential of hydrogen produced from biomethane or biogas to reduce emissions is considerable. Although these processes are not yet available on a large scale, this approach should be pursued further. This is because the growth of plants, their utilisation and the separation of carbon enable the creation of a ‘CO₂ sink’.

In order for Germany to become climate-neutral while remaining an industrialised country, it is necessary to use the gas infrastructure for the provision of hydrogen. The 26,300-mile gas transmission network can be used to transport large quantities of hydrogen over long distances to supply areas both nationally and internationally. Concrete plans for converting existing transmission pipelines from natural gas to hydrogen are already in place, and the relevant DVGW regulations are also available.

Hydrogen often has to travel long distances from the point of production to the consumer. To reduce the volume, it is compressed to high pressure for transport in pipelines. As the gas flows through the pipeline, the pressure decreases. To compensate for this, compressor stations are located at regular intervals in the transmission network to increase the pressure of the gas again and thus maintain the gas flow. Compression is no longer necessary in the distribution network, which transports the gas to consumers.

On its way to the consumer, the hydrogen passes through various pressure stages in the pipeline network. The gas pressure control and measuring systems (GPRM systems) form the necessary interfaces between the different pressure stages along the entire transport route and adjust the pressure to the downstream network, i.e. they reduce it to the required value. At the same time, the quantity of hydrogen transferred and its composition with regard to possible accompanying substances is measured. Often, the GPRM systems also separate the networks of different owners and measure the transported quantities. In addition, a substance is added to the naturally odourless hydrogen when it is fed into the distribution network in the GPRM systems, which produces the characteristic, sulphurous smell that we know from natural gas.

With around 25 storage operators and over 40 underground gas storage facilities, Germany is one of the world's largest storage nations after the USA, Russia and Ukraine. Gas storage facilities, along with gas networks, are an essential part of the gas infrastructure. A large proportion of these underground storage facilities can be converted and used to store hydrogen. The existing infrastructure of underground and above-ground storage facilities in Germany can store large quantities of gas and hydrogen. About a quarter of Germany's annual gas demand is available to industry, commerce and private consumers across the country around the clock. Using hydrogen from gas storage facilities in gas-fired power plants can help to balance out the fluctuating supply of electricity from renewable sources, even over longer periods of time.

The gas distribution network, which is around 343,000 miles long, connects to the gas transport network, through which large quantities of hydrogen will flow over very long distances in the future. This enables the direct supply of climate-neutral energy to over 13 million household customers and almost 1.8 million industrial and commercial enterprises. The pipes have a smaller diameter than those in the upstream gas transmission network and are usually made of steel or plastic.

Today's well-developed gas infrastructure forms the backbone for the future nationwide supply of hydrogen and other climate-neutral gases. The plan is to make the entire gas network fit for pure hydrogen. However, adjustments are needed to ensure that all network components and gas applications are suitable for hydrogen. The gas system can be cost-effectively upgraded and expanded for the future distribution of hydrogen at a manageable additional cost. The German gas distribution network operators are already working intensively on plans for converting their networks to hydrogen. You can find out more here: www.h2vorort.de (in German only)

To achieve the climate protection targets in the industrial sector, fossil energy sources need to be replaced by climate-neutrally produced gases such as hydrogen, biomethane and SNG (synthetic natural gas produced from green hydrogen). In Germany, industry is the largest consumer of natural gas, using it for energy generation and also directly as a raw material in production. The gas grid, to which almost 1.8 million industrial and commercial enterprises are connected nationwide, plays a central role in the transformation to a sustainable industry. In the future, climate-neutral gases will be transported via this grid, enabling Germany to achieve its climate targets while remaining a future-proof, competitive industrial location. 

Gas-fired power plants are particularly well suited to ensuring a secure electricity supply when there is little sunshine or wind, and when there is insufficient electricity available from renewable sources. This is known as dark, windless periods. Gas-fired power plants can start up and reliably produce electricity in a very short time, regardless of the time of day or weather conditions. This means that they play a central role in the German electricity supply. New gas-fired power plants are being designed and built so that they can be operated not only with natural gas but also with hydrogen, and can thus be used for climate-neutral and reliable power generation. 

Almost half of all households in Germany use natural gas for heating and are connected to the well-developed gas network. However, this form of heat generation causes CO₂ emissions and thus damages the climate in the long term. For this reason, fossil natural gas will be gradually replaced by new, climate-neutral gases such as hydrogen in the future. This will make climate-neutral heating possible without the need to completely change the heating technology or to carry out extensive energy-efficient renovation measures.

From 2025 at the latest, gas heating systems will be available that can be operated with natural gas and biogas as well as with 100% hydrogen. As a general rule, a heating appliance should be replaced every 20 years. In the coming years, this will affect millions of heating systems that currently use natural gas, oil or other fossil fuels. If this natural replacement cycle is utilised, at least two-thirds of all heating systems could already be fully replaced by H2-ready appliances by 2030. Buildings heated with green hydrogen would thus be carbon-neutral. This means that even period properties and buildings without a high energy efficiency rating can be heated quickly and cheaply in a carbon-neutral way.

More than 1.8 million industrial and commercial customers are currently still using natural gas for heating their buildings or for various production processes. One distinguishes here between space heating and process heat. To generate these in a climate-neutral way in the future, natural gas must be replaced by hydrogen. From bakeries to breweries and butchers – they all depend on the use of new, climate-neutral gases to continue producing bread, beer and sausage. In the future, hydrogen will also be used to generate heat and steam in laundries and market gardens in a climate-neutral way.

We need to develop solutions that enable climate-neutral mobility and are also capable of sustainably shaping global logistics in addition to private transport. With hydrogen, renewable energy can be stored long term and used anywhere in an environmentally friendly way. Hydrogen is therefore also highly promising for mobility, and it is already becoming apparent that fuel cell-powered vehicles will establish themselves alongside electric vehicles. The planned expansion of production and transport capacities in the hydrogen economy will support this process in the long term. The infrastructure of hydrogen filling stations is currently being developed. An interactive filling station map shows where you can already fill up with hydrogen.