What is LNG?
LNG stands for Liquified Natural Gas. The gas becomes liquid due to extremely low temperatures of around -162 C. At the same time, it loses a lot of volume as a result – liquefied liquid natural gas only takes up about six hundredths of the space as in the gaseous state. In this state, it is brought to Wilhelmshaven or Brunsbuttel in huge transport ships whose tanks are often equipped with special double-walled nickel steel.
LNG – which consists mostly of methane – is not to be confused with LPG (Liquified Petroleum Gas), which means a mixture of propane and butane. In contrast to liquefied natural gas, liquefied petroleum gas (LPG) is liquefied by compression. It is produced, among other things, as a by-product of refining petroleum into petrol. Among other things, this can also be used to operate cars if they have been converted accordingly.
What is a (floating) LNG terminal?
The terminal is not a fixed facility, such as at an airport, but a special ship that is firmly moored and connected to the infrastructure on land via cables. A tanker with LNG on board can moor on this ship. There the LNG is then returned to its original gaseous state. The terminals are therefore also called Floating Storage and Regasification Units (FSRU). There are only about 50 pieces worldwide.
The RWE company, for example, has chartered two FSRUs that are around 300 meters long on behalf of the German government. According to RWE, each of the ships can take up to 170,000 cubic meters of LNG in one unloading process, convert it to the gaseous state on board and then feed it into the gas network. Around ten billion cubic meters of natural gas can be processed in this way every year. Annual consumption in Germany is around 90 billion cubic meters.
What happens to the gas in the terminal?
First, the LNG is pumped through pipes from the tanker to the terminal. There it is then heated with the help of heat exchangers and converted back into gas. These often use the heat of the lake water or they burn part of the gas and use this heat. The natural gas, which is then in gaseous form again, can then be pumped ashore from the terminal via pipelines. The operators assure that it is a closed system and therefore no gas can escape.
How does the gas get into the German grid?
From the terminal, the gas is routed ashore, where it flows through a gas measurement system, which measures the amount of gas delivered or checks whether the pressure is correct. The station in Wilhelmshaven is then to be connected to the national gas network via a 26-kilometer pipeline. It leads to the Etzel connection point and is about halfway done. The work should be completed by the end of December. The pipes should initially be able to transport ten billion and later up to 28 billion cubic meters per year. In addition, it should also be possible to use it for green hydrogen in the long term. In Brunsbuttel in Schleswig-Holstein, too, a new, three-kilometre-long pipeline is to be completed this winter.
In addition to Wilhelmshaven and Brunsbuttel for the coming winter, two other terminals were already planned: According to the government, one in Stade and one in Lubmin on the Baltic Sea coast will be operational by the end of 2023. In Lubmin, a private consortium has also launched an additional one.
What do environmentalists say?
Resistance to liquid gas terminals comes mainly from nature and marine conservationists: The German Environmental Aid criticizes the energy company Uniper in Wilhelmshaven, when importing the gas, discharged large quantities of environmentally harmful substances into the North Sea – without prior environmental testing.
The main concern here is chlorine, which is used in the conversion of LNG. Because in order to be able to transport the liquefied and cooled gas, it must first be heated. This is done using seawater to which chlorine is added so that algae and mussels do not clog the systems. The water then flows back into the North Sea – a danger to the food chain, criticize environmentalists.
According to environmental aid, the terminal ship "Hoegh Esperanza", which is to import liquid gas via Wilhelmshaven, has not received an operating license because of the discharge of this "process water" at its previously planned location in the Australian state of Victoria in 2021. In the environmental assessment of the local authorities, which is available to the German Environmental Aid, the ship failed – and the entire LNG project was then canceled.
"In Wilhelmshaven and at the other LNG locations, there is a threat of a creeping chemical accident," says the federal director of environmental aid, Sascha Muller-Kraenner. According to the application documents, Uniper wants to discharge ten times as much biocide into the North Sea with its LNG terminal ship as the Australian authorities had previously considered acceptable at a comparable location.
The environmental impact assessment is intended for precisely such cases. The environmental aid is therefore calling for the previously omitted tests to be carried out immediately for all planned LNG projects. A company may only be approved if the input of biocides is reduced to the absolutely necessary minimum.
What about the climate balance?
When natural gas is burned, CO2 is always released – the fuel is never climate-friendly. With LNG, there is also the fact that the liquefaction process, the cooling to less than minus 160 degrees Celsius for transport and the transport itself are very energy-intensive. All of this means that LNG is generally more harmful to the climate than natural gas, which is transported via pipelines.
The origin of the gas also plays a major role: the USA in particular requires large quantities of gas with the controversial fracking process. It is pressed out of rock pores under high pressure; in the case of older technology, a chemical cocktail is used. The procedure is forbidden in Germany.
An example: A four-person household consumes an average of one gigajoule of natural gas in a week. Burning alone releases 56 kilograms of CO2. If the natural gas comes as LNG from the USA and is required by fracking, another 24 kilograms of CO2 emissions are added. With pipeline natural gas from Norway, on the other hand, only around four kilograms of additional CO2 are emitted.