Glossary

Generating unit

A generating unit for electrical energy is a component of a power station that can be defined by certain criteria. This could for example be a block-unit power station, a busbar power station, a combined cycle facility, a wind turbine, a machine unit in a hydro-electric power station, a fuel cell stack or a solar module.

German Renewable Energy Act

The German Renewable Energy Act (Erneuerbare-Energien-Gesetz or EEG) prescribes the preferential inclusion and remuneration for energy generated from renewable sources such as water, wind, biomass, landfill gas, sewage gas, as well as PV by the relevant system operators. Since 1 January 2017, the level of remuneration is determined by a process of open competitive bidding, replacing a fixed-price system. The EEG obliges the transmission system operators to cooperate in order to ensure a load balance as well as remuneration. To discharge these obligations, the transmission system operators sell EEG energy at an energy exchange. The revenue generated from the sales as well as the revenue from the EEG-levy are used to cover expenses (primarily remuneration payments). The EEG-levy is imposed by the energy supplier on the end consumers and passed on to the transmission system operators.

GIS construction

A gas-insulated switchgear structure that has been specially developed for use in substations. This construction method reduces the volume of the substation, meaning that a much smaller floor area is required than previously. This therefore makes the substation suitable for installation at locations with limited space.

Grid connection
The network or grid connection refers to the technical connection of consumer installations to a grid.
Grid connection point (GCP)

The technically and economically most favourable connection point in the grid connection system to the next transmission or distribution network (onshore substation).

Grid connection regulations
Minimum technical requirements for the connections to the grid.
Grid connection system (GCS)

The umbrella term for all installations used for the transmission of electrical energy between the network connection terminal of an offshore wind farm and the grid connection point using the transmission network. If only three-phase electric power is used for transmission, then this is called an AC grid connection system. If direct current is used for at least one section of the transmission path, then this is called a DC grid connection system.

Grid connection terminal

The grid connection terminal is the point where a grid user’s connection system is linked to the grid. For the grid connection of offshore wind farms, this refers to the point of intersection between the offshore wind farm and the grid connection system.

Grid Development

Grid development is used to refer to measures such as the replacement of operating equipment with more powerful components, the extension of existing transformer stations and substations, for example with additional switchgear devices and/or power busbars as well as the construction of power lines in existing routes. These measures are represented in this report’s maps with solid blue lines or filled-in areas. They include, for example, increasing voltage from 220 kV to 380 kV, increasing cabling or recabling circuits. In line with the NOVA principle that is applied throughout the GDP, a grid development measure is not explored until all other technically and economically feasible options for grid optimisation have been exhausted.

Grid Development Plan

Up until the Grid Development Plan (GDP) 2014, the transmission system operators included the year in which the plan was produced in the title. From the GDP 2025 onwards, the target year was added to the title instead. This change thus brings the plans in line with the nomenclature of the German Federal Network Agency, which has been exclusively using the target year of the ten year forecasts in its communication surrounding the GDP for a long time.

Grid enhancement
Grid enhancement measures are those that deal with the replacement of operating equipment for more powerful components, the extension of existing transformer stations and substations, e.g. with additional switchgear devices and/or power busbars as well as the construction of power lines in existing routes. These measures are represented in the diagrams with solid blue lines or filled-in areas.
Grid expansion

Grid expansion measures describe the construction of transformer stations and substations or power lines in new routes. A yellow shaded area is used to represent these measures in the diagrams. The addition of transformers, facilities for reactive power compensation or operating equipment to control active power in existing transformer stations or substations is represented in the maps with yellow shaded areas with blue borders, these fields are marked with “Expansion of existing facilities”.

Grid optimisation
A measure for grid optimisation refers to the use of overhead line monitoring for a circuit or adjusting the operating voltage of a circuit to a higher voltage without recabling.
Gross output

The gross output of the generation unit is the amount of power output at the generator terminals. The energy demand of the generation facility itself (e.g. for pumps or cooling towers) is not yet taken into account. In contrast, the net output takes the plant’s own energy consumption into account.