Glossary

The Agency for the Cooperation of Energy Regulators (ACER) is a decentralized European Union agency based in Ljubljana, Slovenia. Founded in 2009, its task is to monitor and regulate the European energy markets to ensure transparency and stability.

GASCADE provides planning, access and operating services for a pipeline network as well as services for technical quantity determination and the provision of gas quality data.

Allocation means the allotment of gas quantities to individual balancing groups.

Approvals must be obtained from the authorities responsible, especially for new construction projects. This process is planned early on.

Basic engineering (draft planning) describes the process for coming up with the best possible design for a system from a technical and economic point of view.
Detailed engineering (execution planning) refers to the detailed design and exact description of all components and measures needed to build a compressor station for example.

Bundesverband der Energie- und Wasserwirtschaft e.V. (the German Association of Energy and Water Industries) represents the interests of its members vis-à-vis politicians, the media and in public. Through its state organizations, it advises and supports member companies as regards sector-related political, legal, economic, technical and communicative issues.

Balancing groups comprise a number of entry and exit points within a network area. They allow both virtual gas flows (trading deals) and physical gas flows to be depicted. The trading deals are passed on to the network operator so that the operator can fulfill them physically - in the form of actual gas transports. The network operator checks both the consistency of the schedules submitted and that they subsequently match the actual energy flows. Deviations from schedules are compensated for by sourcing or supplying balancing energy. With the help of balancing groups, the gas flows (entries/exits) of a Balancing Group Manager are compared and balanced - as with a bank account. If a balancing group is not balanced, the differences are settled as necessary.

A Balancing Group Manager is a market player (e.g. a network user, trader or service provider) who concludes a balancing group contract with the Market Area Manager.

In order to transport gas within a market area, the market player must conclude a balancing group contract with the Market Area Manager. The balancing group contract sets out details of services which are necessary for administering a balancing group.

The German Federal Network Agency for Electricity, Gas, Telecommunications, Post and Railway (Bundesnetzagentur, short: BNetzA) is based in Bonn. The Federal Network Agency is one of the main government agencies within the German Federal Ministry of Economics. It is the supervisory authority for GASCADE.

Measurement of the energy contained in gas. The calorific value depends on the chemical composition. The chemical composition varies according to the source of the gas and the mixing within the gas distribution networks. Depending on the calorific value, the terms generally used are  L gas and H gas

The Comité Européen de Normalisation / European Committee for Standardization / Europäisches Komitee für Normung (CEN) is responsible for European standards (Europäische Normen, short EN) in virtually all technical areas. GASCADE is a member of CEN working groups.

Maximum hourly flow rate at an entry or exit point in kWh/h.

Maximum hourly flow rate at an entry point or exit point within a specific period. It is expressed in cubic meters per hour or kilowatt hours per hour.

A statistical and fluid mechanics calculation procedure which is used to determine marketable capacities.

If the natural environment and the landscape are impaired as a result of a new pipeline or facility being built, the builder must pay compensation to make up for impairments.

A drawing like this serves as a basis for producing parts for a new facility, for example.

Energy quantities for physically balancing (system stability) the gas networks in a market area. A distinction is made between internal control energy through the use of network buffering (line pack) and external control energy. External control energy is bought on a market basis at natural gas trading points (exchanges, Virtual Trading Point, control energy portals of the Market Area Managers) and on the basis of calculations of the transmission system operators (TSOs) in the market area and the Market Area Manager.

A system that compresses natural gas to the pressure needed to reach the exit point (with contractually defined pressure values) or the next compressor station. A compressor station can comprise a number of compressor units. Each compressor unit is made up of a drive unit (gas turbine or electric motor) and the actual compressor. A compressor system also has other auxiliary systems, e.g. electrical energy supply, process management system, field instrumentation, pipelines, valves, building infrastructure, drive energy preparation, fire and gas warning system, building protection, safety systems and fire extinguishing systems.

Compressing the gas reduces its volume. This means that more gas can flow through the pipeline and the transport capacity of the pipeline is increased. The gas flow is controlled on the basis of different pressures. When gas is transported, it flows because of the differences in pressure – from high pressure to low pressure.

With day-ahead trading on electricity and gas exchanges, the gas or electricity is supplied and paid for the following day.

The German Technical and Scientific Association for Gas and Water (DVGW: Deutscher Verein des Gas- und Wasserfaches) is responsible for producing a set of technical rules which ensures the security and reliability of the gas and water supply. The rules also apply to the thermal quantity determination of natural gas. As a member, GASCADE is involved in producing the DVGW’s sets of rules.

With dynamically allocable capacity, the entry or exit capacities have an assignment restriction. This means that only very specific network points can be reached and the capacity is fixed. Access to the virtual trading point is only possible on an interruptible, “as available” basis. See also interruptible capacity, fixed capacity and freely allocable capacity.

Distribution network operators connected to a pipeline network operator.

As part of incentive based regulation, the Federal Network Agency checks the cost effectiveness of the German transmission system operators. These have to measure themselves against the most efficient operator. The basis for the nationwide efficiency comparison is §§ 12 ff of the Incentive Regulation Ordinance (ARegV). Less efficient companies are given a few years in which to resolve their individual inefficiency.

An entry point is a point in a market area where gas can be fed into a network operator’s network.

Electrical, measuring, control and regulation systems are found in the field of automation technology.

Energy quantity determination describes a process where a calibrated thermal measurement result in [kWh] is produced using remotely transmitted measurement values which are relevant for billing purposes. GASCADE works mostly with IT-based processes.

The entry/exit model describes a model for transport where the network user merely needs to book the entry and exit point within a market area. The transport route is controlled and optimized solely by the network operators in the market area. This model is used in both German market areas.

The European Network of Transmission System Operators for Gas (ENTSOG) is an association of the operators of gas pipeline networks in Europe. ENTSOG is based in Brussels.

If transmission system operators exchange capacities within a  market area at network points, these capacities are referred to as exchange capacities.

An exit point is a point in a market area where gas can be withdrawn from a network operator’s network.

These tools are used to determine how high the permitted, regulated revenue of a network operator can be, in other words, how much it is allowed to earn.
In principle, a distinction is made between an application before incentive regulation (fee application) and an application within incentive application (cost application).
If the network operator is not yet in incentive regulation, but in cost regulation instead, the network operator submits a fee application to the regulatory authority for the approval of fees for a specific approval period. Generally speaking, this only applies to newly established network operators. A network operator that is already in incentive regulation submits a cost application in the year after the base year in each case. On the basis of this application, the Federal Network Agency then approves the upper revenue limit for the next regulatory period.

Capacities that are booked on a fixed basis and cannot be interrupted. The network user can therefore fulfill its delivery obligation at all times. See also interruptible capacity, fixed capacity and freely allocable capacity.

Vereinigung der Fernleitungsnetzbetreiber Gas e. V. (FNB Gas) is a German association which represents the interests of the German transmission system operators for natural gas. It was established in 2012 and is based in Berlin. The association focuses on coordination when producing the Network Development Plan Gas.

Freely allocable capacity is a capacity where a customer can combine a capacity right at an entry point with a capacity right at any exit point in the market area for a specific transport service - or can combine a capacity right at an exit point with a capacity right at any entry point in the market area for a specific transport service. See also interruptible capacity, fixed capacity and freely allocable capacity.

At network points to downstream network operators and final consumers, a forecast (quantity forecast) of exit quantities is carried out in order to determine the future schedule (at least for the current and following gas day). Various forecasting procedures such as temperature forecasts or historical values are used.

Fuel gas is needed to operate compressors and heating systems as well as for maintenance work on the network. Fuel gas is procured via public tendering processes.

GABi Gas is a resolution of the Federal Network Agency (BNetzA) which contains rules for gas balancing. Among other things, it regulates network account billing, control energy levies and the provision of information.

A technical system for volume measurement, revaluation, registration and the remote transmission of measurement values in order to measure the transported energy quantity and manage the gas transport network.

Gas quality is determined by physical parameters (such as the calorific value and Wobbe index) and chemical parameters (accompanying substances). Norms and sets of rules use these parameters to describe gas qualities and define corresponding requirements.

A technical system (process gas chromatograph) for determining the calorific value of the gas transported. Essentially, the hydrocarbon content is analyzed.

GASCADE’s gas quality reconstruction is a system for determining gas quality at any points in a pipeline network on the basis of a simulation model (LINK: SIMULATION). It is approved by the German National Metrology Institute (PTB) and monitored by the Hesse Weights and Measures Department. The gas qualities determined in this way are used in the technical quantity determination process.

A geographical information system (GIS) is an IT application that allows measurement, official and area-related data to be collected digitally, processed and presented graphically. At GASCADE, the GIS system is the basis for producing and maintaining the extensive pipeline documentation.

The aim of the act is to ensure the most secure, low-cost, consumer-friendly, efficient and environmentally-friendly grid-based supply of electricity and gas for the public, with the electricity and gas increasingly being generated from renewable energy sources.
The regulation of the electricity and gas supply networks is designed to ensure effective, genuine competition in the electricity and gas supply industry and the efficient and reliable operation of energy supply networks in the long term.

The gas pressure regulation and measuring system measures natural gas and reduces the pressure when it is fed into and out of the pipeline network.

High-calorific natural gas whose calorific value is between 11.0 and 12.5 kWh per standard cubic meter. It comes from Norway and Russia. See also L gas.

Incentive-based regulation came into force in 2009 with the goal of encouraging the operators of gas and electricity networks to reduce costs and pass on the savings to consumers. Network operators are given upper limits for their fees or - as in the case of GASCADE - upper limits for revenue. The basis for this is the German Incentive Regulation Ordinance (ARegV)) which was amended in August 2016.

Incident management is used in the event of a network fault. During an initial analysis carried out by the dispatching center, the incident is classified and categorized into one of three incident categories: HSE, transport restriction and safety. If the incident satisfies specific criteria, the GASCADE crisis team is called in.

An investment measure in accordance with § 23 of the ARegV is designed to allow network operators to include expenditures in the upper revenue limit early on. The BNetzA approves investment measures for expansion and restructuring projects if they are necessary for the stability of the overall system, for integration into the national or international interconnected network or for needs-based development of the energy supply network. In accordance with § 23 Sect. 3 of the ARegV, the application should be submitted no later than nine months before the start of the calendar year in which the investment will become cost-effective. Operating and capital costs can be claimed as costs.

The network operator can interrupt these capacities at any time. See also dynamic capacity, fixed capacity and freely allocable capacity.

Low-calorific natural gas whose calorific value is around 10.0 kWh per standard cubic meter. It comes from Northern Germany and the Netherlands. See also H gas.

The Market Area Manager fulfills all duties in accordance with the German Energy Management Act within a market area. It balances all gas flows and compensates for any differences which occur. In order to do this, balancing group contracts are concluded with the Balancing Group Managers.

At specific intervals, checks are carried out to ensure that the measuring devices are functional and accurate. All measuring devices required to determine the volume and chemical composition of the gas are checked.

The term management system refers to a higher-level control software tool which can monitor, visualize, control and regulate an entire network infrastructure. At GASCADE, the majority of control functions are provided automatically with the help of programmable logic controllers (PLC) at the GASCADE stations.

One of the tasks of the higher-level management system is to output regulating variables and target values in order to achieve the optimum network status. A further task is to collect and archive measured values and status information such as switch settings. The data is prepared in a standardized, user-friendly format and allows the dispatcher to intervene in the process for control purposes.

The capacities available at network points, taking into account capacities which are already booked.

The network connection comprises the network connection system, the network connection pipeline and the network point (in the form of a network coupling point or a network connection point).

A network connection contract is concluded between a gas transmission system operator and a final consumer connected to its network. It contains among other things provisions regarding the property boundary, the exchanging of information, capacity, the allocation procedure and liability.

The network connection point marks the property boundary between the network operator and the final consumer.

A network coupling contract is concluded between two neighboring gas network operators. It contains, among other things, provisions regarding the property boundary, the exchanging of information, capacity, the allocation procedure and liability.

The location where two gas networks are connected physically (usually by a gas pressure regulation and measuring system) is referred to as a network coupling point. The network coupling point marks the property boundary between two neighboring network operators.

The location where two gas networks are connected physically (usually by a gas pressure regulation and measuring system) is referred to as a network coupling point.

The German Energy Management Act requires the pipeline network operators to produce a joint Germany-wide Network Development Plan (NDP) every year. The plan must contain details of all effective network-related measures which are required over the next ten years in order to ensure safe and reliable network operation. These include measures for needs-based optimization, the needs-based upgrading and development of the network and measures for guaranteeing supply security.

A network point is a physical point in a network to which further networks (see network coupling point), producers, gas storage facilities or consumers (see network connection point) are connected. The term can apply to a network connection point and a network coupling point.

Software-supported network simulation is used to calculate flow statuses in the gas network. The flow statuses are calculated in a transient manner, in other words, the permanent changes in the flows are taken into account correctly.

The input data for the simulation are schedules at the network points, gas qualities, gas temperatures, pressure values and the complete geometry of the network segments (including pipe lengths, diameters, roughness). Depending on the type of simulation, these are either measured data or values from the forecast and the quantity and operational planning (dispatching).

As a result, the simulation can be used in various contexts:

• Process-related simulation for calculating the current network status
• Predictive simulation variants

In addition to ensuring the reliable transport of gas, the transmission system operator must also ensure network stability, in other words, ensure that all customers receive the assured quantities. In order to do this, a specific minimum gas content must be retained in the relevant pipeline sections in order to maintain the prescribed pressures.

With high transport volumes, the minimum content in a pipeline is greater than with low transport volumes owing to the higher pressure. The difference between the maximum and minimum content is expressed in a pipeline’s buffer volume. During day-to-day business, this gas is needed to compensate for the fluctuations in the quantities of gas released and sourced. It serves as a reserve in the event of supply problems. 

A nomination informs the network operator about the extent to which a transport contract is to be used for a specific time period. The gas network operator controls the gas flows in its network on the basis of nominations. If a nomination is changed, this is referred to as a renomination.

With the so-called matching process, neighboring network operators compare nominations on both sides of a network point. If there are nominations on an equal level on both sides of a network point, a corresponding gas flow will be controlled at the relevant network point. If there are nominations on different levels at both sides of the network point, the lower value will be taken into account when controlling the gas flow.

Actually the base year: The year in which, in accordance with § 6 of the ARegV, the regulatory authority calculates the starting level for determining the upper revenue limits on the basis of a cost check. The cost check is carried out in the penultimate calendar year prior to the start of the regulating period. It is based on the data from the last full financial year.

Supply companies are required to document their own pipeline network. The documentation is used for a variety of purposes, e.g. to produce inventory plans, for operational management and to visualize the sites affected by the pipeline route.

In order to ensure safe pipeline operation, companies carrying out planning or construction work must investigate the routes of underground supply pipelines (third-party planning inquiries) before a construction project begins. GASCADE then provides information regarding the routes of its own pipelines close to the project location and possible conditions. At GASCADE, pipeline information is issued on the basis of the pipeline documentation in the geographical information system (GIS).

Supply companies need to use property belonging to third parties in order to lay and operate pipelines. Generally speaking, the pipeline rights needed to do this are secured as a limited personal servitude in the land registry and appropriate compensation is paid.

The planning approval procedure is an approval procedure under public law for major infrastructure projects (e.g. natural gas pipelines). A particular feature of the planning approval procedure is that it has a “concentrating effect”, in other words, the planning approval decision replaces all other approvals. When making a decision, the planning approval authorities weigh up all public and private issues.

The idea of power to gas is to store electricity generated from renewable energy sources. In the process, the excess electricity generated is used to produce hydrogen and in turn methane which barely differs from the natural gas found in nature. Because methane is the main constituent (approx. 93 %) of conventional natural gas, this synthetically produced gas can be integrated into the natural gas infrastructure with no quantity restrictions. If necessary, it can be converted back to electricity.

PRISMA is a European capacity booking platform which was founded by European transmission system operators in 2013. Via PRISMA, the available capacities of the TSOs are marketed (primary capacity trading) and network users are able to trade capacities between themselves (secondary capacity trading).

A process managing system is used to manage a technical system, e.g. a compressor station. Process managing systems are mainly used for larger systems and usually consist of a package comprising the following mechanisms

• Process-related components for controlling regulators and valves and for recording measured values
• Alarm system
• System visualization
• Recording of analog measured value curves
• User management
• Engineering options
• Technical diagnostics options
• Data interfaces to external systems
• Automation units for more demanding control systems
• Data backup systems

The management system at the dispatching center is a special case. It combines the functions of various process management systems in the compressor stations with software applications simulation, forecast and business partner communication.

The abbreviation stands for 24 hours a day, 7 days a week. Or, in other words: Our dispatching center which controls all gas flows is in operation around the clock. 

Map with pipeline routes

With the so-called schedules, all network points as well as facilities in the pipeline network can be actively controlled via an IT application. For example, the gas quantities to be transported can be regulated at network points or in network segments. Individual regulating devices, complete regulating stations, compressor units and entire compressor stations can be controlled.

RDT allows data to be transferred from the local measuring system to the GASCADE headquarters in Kassel. Measured values, meter readings, reports, gas qualities, parameters and time settings, etc. can be transferred in this way. In the GASCADE pipeline network, data is mainly retrieved via LAN adapters and the company’s own fiber optic (FO) communication network.

At the reporting point or dispatching center, reports concerning the pipeline network can be received around the clock, seven days a week, in order to ensure smooth operation. The contact data for the dispatching center can be found, for example, on the yellow marker posts along the pipelines.

A regional planning procedure (RPP) sets out a rough pipeline route. Application conferences take place prior to the regional planning procedure. During these official events, local government bodies (towns and municipalities, specialist authorities and recognized associations and organizations) decide on the area along the route to be investigated and the method of investigation.
The responsible authorities then examine the preferred route and potential alternatives during the regional planning procedure. The various impacts of the routes on people, nature and the environment are assessed. At the end, the authorities decide which route will have the least impact on the local area. However, the regional planning procedure only determines a route corridor – an exact route is not determined until the planning approval procedure.

More specifically "market regulation" – this refers to direct state intervention in economic processes which usually takes place where the market is to be controlled, e.g. where there are natural monopolies. Network access agreements and above all market access, pricing and tariff agreements are often realized in a way that a monopolist cannot exclude potential competitors from network use. GASCADE is subject to so-called incentive regulation.

A nomination informs the network operator about the extent to which a transport contract is to be used for a specific time period. If the announced transport quantities are subsequently changed, this is referred to as a renomination.

During route planning, various routes are developed and compared from an economic, environmental and technical point of view.  The scale for the investigation is still relatively large (1:5000 to 1:25000 on a map). By weighing up all the advantages and disadvantages a preferred route is then determined and further refined .

The schedule is a tool for administering the exchange of gas quantities between two network operators. The schedules state how much energy (measured in kWh/h) is exchanged between the network operators at the network point and how much is fed in/out at the entry/exit point for each hour within the planning period. The schedules for all network points provide flexibility as regards quantity and operational planning for the entire network.

A substitute nomination procedure is a service which a number of network operators offer their customers. In this case, the network operator reports quantities to the Market Area Manager which are used as a substitute for nominations when defining allocation values. 

When planning and operating the pipeline network, it is important to measure exactly the local features of the site as well as the location and altitude of the supply pipelines. All measurement results and data are transferred to a geographical information system in which the pipeline documentation is produced.

The following aspects are important for supply security:

• the gas network must be able to fulfill the transport tasks
• robust regulating mechanisms must ensure that network stability is maintained even if gas entries and exits are not balanced
• the networks must be adequately secured against third-party interference (IT security)

The transport quantity per network point or network segment is the result of quantity and operational planning.

Quantity and operational planning in a network is optimized with the help of software. The aim is to determine and put in place the most efficient network operation (lowest drive energy costs and minimum use of resources) under the given conditions (schedules).

A transport contract is concluded between a gas transmission system operator and a network user on the PRISMA or RBP platform. It authorizes the network user to transport a specific quantity of natural gas to a specific network point for a specific period.

The upper limits for a network operator’s permitted total revenue from network fees (upper revenue limit) are set on the basis of the stipulations in the Incentive Regulation Ordinance. The upper revenue limit is determined by a cost check. In addition to the approved costs (including basic costs, depreciation, calculated return on equity), investment measures, compensation for inflation and the regulatory account are taken into consideration.

Unbundling generally means establishing or boosting the independence of various business areas of a company or a group of companies. This is done due to legal (anti-trust law) and/or regulatory requirements. In the case of so-called grid-based network industries (energy, rail, telecommunications), unbundling focuses on separating the network infrastructure operations from the upstream and downstream value creation stages of the relevant network industry (production/sales)

Pipeline network operators that transport the gas to downstream network operators.

At the virtual trading point, natural gas can be traded after it is fed into and before it is fed out of the market area. Balancing group managers  can exchange gas quantities between balancing groups. The VTP is managed by the Market Area Manager.

The virtual trading point is not assigned to any physical entry or exit point and enables buyers and sellers to buy and sell gas without booking any capacity.

The abbreviation stands for 24 hours a day, 7 days a week. Or, in other words: Our dispatching center which controls all gas flows is in operation around the clock.