Processes for Determining Technical Capacity

Basics of Capacity Determination

The following information in particular is used to determine the technical capacity of the entry and exit points:

  • the topological information about the network, in particular the nominal diameter, length and pipe roughness of the individual pipe sections, the performance parameters of the feed-in and feed-out stations as well as the grid-connecting stations and the design pressures of the installed components,
  • the contractual boundary conditions at grid interconnection and grid connection points as well as technical requirements at the grid-connecting stations, in particular contractual and technical maximum and minimum pressures
  • the gas quality parameters at entry points

This information is supplemented by contractual agreements on already marketed entry and exit capacities (capacity contracts) as well as contractual commitments in grid interconnection and grid connection contracts/storage connection contracts. The requirements of biogas entry points must also be taken into account.

Evaluations of the consumption behaviour of the connected or downstream consumers are prepared for all exit points in order to develop temperature-dependent load scenarios for the grids or grid components.

These load scenarios are compared with feed-in scenarios under the premise of a balanced grid (feed-in equals feed-out), i.e. the feed-in capacities are initially defined on the basis of the performance of the feeding stations or from contractual agreements and the utilisation of the feed-in capacities is varied within the framework of the existing flexibility.

Pipe network calculations are used to check all contractual pressure boundary conditions and operating ranges of compressor stations and gas pressure regulating and metering systems as well as the relevant technical limit values for the combinations of entry and exit scenarios. As long as none of these boundary conditions are violated, the defined entry and exit capacity can be assumed and marketed as firm technical capacity at the respective points. If the aforementioned constraints are violated, the capacity must be reduced at suitable points to such an extent that the constraints are met. As a rule, marketed capacity does not have to be reduced.

In the event of requests for new or additional technical capacity, this process is repeated, taking into account the priorities for biogas and gas-fired power plants, storage facilities and production plants specified in the GasNZV, whereby free technical capacity at entry and exit points is relocated as far as possible and technically feasible in order to satisfy the requests. If the demand cannot be met within the existing infrastructure, suitable expansion measures are planned in accordance with efficiency requirements and implemented if economically feasible.