In order to ensure security of supply in line with increasing demand, it is necessary for terranets bw to develop the gas transmission system. One of these pipeline development measures is the construction of a gas compression station on the “Nordschwarzwaldleitung” gas pipeline Nordschwarzwaldleitung.
The Networkdevelopmentplan Gas (NDP Gas) comprises all measures for optimising, strengthening and developing the network in line with demand as well as for ensuring security of supply. From a technical perspective, these measures will be needed in the next ten years to guarantee secure and reliable grid operation.
Natural gas travels thousands of kilometres through international and national pipelines before it reaches consumers. The compressor station compresses the gas and increases its pressure and this means that more gas can be transported through the pipeline. The transmission capacity of the pipeline thereby increases – and consequently also the security of supply for consumers.
The new gas compressor station on the pipeline “Nordschwarzwaldleitung” is to be built in Rheinstetten in the Hardtwald region south of the radio mast between the L566, the B3 and the A5. Construction is scheduled to begin when approval has been granted in spring 2021. Commissioning is expected to be in the year 2023.
|4||Machine units, consisting of a compressor and engine|
between 6 and 9 p.m.
|Info Market “Gasverdichterstation an der Nordschwarzwaldleitung“|
Dammfeld 9, 76287 Rheinstetten
A gas compressor station compresses the gas, thereby increasing its pressure. This means more gas can be transported through the pipeline and the transmission capacity of the pipeline increases – and consequently also the security of supply for the consumer. In Germany, there are about 70 gas compressor stations that are operated especially when increased capacity demand is required – that means mainly in winter.
Gas flows through underground pipelines and reaches the compressor station at a pressure of 40 bar. First, dust and moisture are filtered out and subsequently the gas is led to the compressor and is brought to the required pressure. A turbine or an electric motor provides the energy needed for the compression process.
The compression process heats up the gas to a maximum of 70 °C. It is therefore passed through gas coolers that cool it down to operating temperature again. The gas is then led through a metering section before being fed back into the terranets bw transmission system at a pressure of 80 bar.
The regional grid operators (e.g. municipal utility companies) connected to the terranets bw network have been reporting a continuously increasing demand for gas transmission capacity for years – by 2030 demand will have increased again by about 30 % compared to 2020. The reasons for this increase are the replacement of coal and oil (Fuel Switch) by gas, the resulting increased demand brought about by gas-fired power stations and in the heating market alongside new connections and developments.
Site selection was preceded by detailed studies in which terranets bw considered various influencing factors in addition to legal stipulations and technical requirements. This includes, in addition to protected areas, distances to residential areas, land use plans and information from the municipalities. After intensive surveys and in close collaboration with municipalities, authorities and associations, a site for the new compressor station was identified. Special attention was also given to its low visibility in the landscape. In the approval procedure the Regional Council of Freiburg, as the responsible approving authority, decides whether the station can be built and operated at the suggested site.
A photomontage shows what the gas compressor station at the site in Rheinstetten could look like. The picture shows the machine hall, which will house four machine units consisting of compressor and main engine. Next to it there will be an administration building. (cf. How does a compressor station work?)
Construction and operation of a gas compressor station is subject to public-law approval in accordance with the Federal Immission Control Act (BImSchG). The relevant approving authority is the Regional Council of Freiburg. In order to achieve a broad consensus with all parties affected by the project, terranets bw involved the respective municipalities and other stakeholders at an early stage.
Transmission system operators in Germany are obliged to ensure a future-viable gas supply by developing their network. As an independent transmission system operator for gas in Baden-Württemberg, terranets bw is responsible for building the gas compressor station.
Ready to operate, the planned gas compressor station requires an area of approx. 6 acres (25,000 m²). This is roughly equivalent to the size of three football pitches. During the construction phase, additional space is needed for building site equipment and its storage.
For the construction phase, additional space is temporarily required for building site equipment and its storage.
Increased traffic is to be expected due to suppliers delivering materials via the access roads. On completion of the construction measures, the areas required for temporary use (space for building site equipment and storage as well as access roads) will be restored to their original state and can be used for agricultural purposes once again. Damage to land and plants caused by this temporary use will be compensated at fixed rates.
When the gas compressor station is in service, the noise load at the site fence amounts to about 60 dB(A). This is comparable to a television set at room volume. The noise load at a distance of 350 m is then about 35 dB(A). This level is within the legally prescribed limits for a quiet residential area. The distance between the planned gas compressor station and the nearest residential area will be more than 350 m. Generally speaking, the local noise situation is characterized by the neighbouring roads (A5, L566, K3581).
In the planning phase, surveys related to the anticipated noise emissions will be carried out by experts. The results of these surveys will serve to determine and dimension the noise protection measures required to comply with the legal noise protection limits.
Operation and maintenance works are carried out by terranets bw qualified employees. As with the whole transmission system of terranets bw, the gas compressor station is monitored and controlled by the dispatching centre, which is manned 24/7.
Compliance with legal and technical requirements is controlled and monitored by the state energy regulatory authority and changes must be signed off by state recognized experts. The regulatory authority for terranets bw is the regional office of the Regional Council of Freiburg (Landesbergdirektion des Regierungspräsidiums Freiburg).
The construction phase and commissioning of a gas compressor station is expected to take about two years. This period includes connecting the site to utilities, building construction, installation of compressor technology and the renaturalisation of the area surrounding the buildings at the site.
Construction is expected to begin as soon as approval is obtained in spring 2021. Commissioning is planned for the year 2023.
Planning up to renaturalisation: the project timeline
In order to minimise the impact on nature and environment, terranets bw takes numerous precautions throughout the whole planning and construction processes. At the beginning of the planning phase, terranets bw examines the existing natural surroundings and landscape in detail and assesses the impact on plants, animals, ground, water, climate/air, landscape and human beings as well as on cultural assets.
Measures were derived from the survey results to avoid or mitigate impact on the environment. This meant that the location of the compressor station, access roads and gas connection pipeline were adjusted in order to preserve as complete a forest edge as possible. The forest edge is important for bats as a guiding structure and additionally provides a natural screen for the gas compressor station. Besides this, permanent lighting of the gas compressor station will be avoided and insect-friendly light will be used. During the construction period, measures to protect reptiles and amphibians will be implemented.
Unavoidable, permanent damages will be compensated by corresponding measures (compensation measures). Besides planting new trees, it is also planned to put up for example nesting boxes and brooding aids for breeding birds and bats as well as to improve a humid biotope in Rheinstetten.