AC connection

An AC connection is used to carry generated electrical energy from the transformer platform of an offshore wind farm to a converter platform (for DC grid connection systems) or to a bundling point (for AC grid connections systems). From here, the electrical energy is transmitted via a HVDC transmission line or an AC transmission line to an onshore grid connection point.

AC direct connection concept

The electrical energy generated by an offshore wind farm is transmitted via intra-farm cabling directly to a converter platform (in the case of DC grid connection systems) or transformer platform (in the case of AC grid connection systems). From here, the electrical energy is transmitted via an HVDC transmission line or an AC transmission line to the onshore grid connection point. The intra-farm cabling of the offshore wind farm is not part of the DC or AC grid connection systems.

AC grid connection system
AC transmission line

The "Agency for the Cooperation of Energy Regulators" is the regulatory agency for Europe. Its primary function is to coordinate and provide advice. One of its main tasks is the composition of non-binding guidelines, which ENTSO-E uses as a basis for developing network codes. Other tasks include the coordination of investments and infrastructure-related measures as well as monitoring the operational capability of the European electricity and gas sector.

Actual grid

The actual grid is the grid as it currently exists today.

Actual offshore grid, initial offshore grid

The initial offshore grid is the point of departure for planning work for the offshore extra-high voltage grid. It comprises the actual offshore grid supplemented by grid connection systems for offshore wind farms which have been approved by the transmission system operators (TSOs) obliged to create this connection.

In accordance with Section 17e (2) of the Energy Industry Act, this obligation applies to offshore wind farms that have been given unconditional approval for connection to the grid by 29 August 2012 and offshore wind farms that were initially given conditional approval for connection to the grid and which satisfactorily demonstrated fulfilment of all criteria for unconditional approval by 1 September 2012.

Alternating current (AC)

Alternating current (AC) is the term for a flow of electricity that periodically reverses direction (polarity) and for which the positive and negative instantaneous values complement each other so that over time the average current is zero. Three-phase alternating current is also referred to as three-phase current.

Annual peak load

The annual peak load is the maximum demand for electrical power occurring in a grid in one year.

Apparent power

Apparent power is the Pythagorean sum of active power and reactive power.

Auxiliary power supply

The auxiliary power supply is needed by the operational facilities and secondary structures for the operation of grid connection systems and offshore wind farms.