Explanation of Used Terms
Term | Abbreviation | Description |
|---|---|---|
Air Mass | AM | The air mass describes a relative measurement for the length of the path that sunlight covers through the earth's atmosphere to the ground. When sunlight strikes vertically, the air mass is 1.0. The radiant power would be at its maximum at this point. The radiant power decreases the more the sunlight strikes the earth at an angle. |
Automatic reconnection | AWE | Protection requirements on the part of the grid operator |
Electrotechnical Properties Verification Ordinance | NELEV | Describes the legal basis for what evidence must be provided for generating systems and battery storage systems. |
Energy System Requirements Ordinance | EAAV | Regulation with supplementary requirements to the VDE-AR-N 4105 for systems that no longer have to undergo system certification as per VDE-AR-N 4110 according to the new NELEV (revision 2024). |
Generation Unit | PGU | Technical unit for the generation and feed-in of electrical energy (here: inverter) |
Grid connection point | POI | Point of common coupling of the overall customer system to the grid operator |
Forum network technology/network operation | FNN in the VDE | Organization within the VDE, which formulates the technical connection rules in cross-association work groups. |
Monitoring the feed-in power at the point of interconnection | PAV,E monitoring | Describes the monitoring, curtailment and possible grid disconnection of generating systems when the agreed feed-in power at the point of interconnection is exceeded according to specified requirements. |
Installed maximum active power of the generation unit | PEmax | Maximum AC active power (10 min average) of an inverter according to unit certificate as per VDE-AR-N 4110. Usually corresponds to the nominal power. |
Installed maximum reduced active power of the generation unit | PEmax,red | If an inverter is limited in the active power permanently and protected by a password, then PEmax,red is to be used in place of PEmax. When the active power in inverters is reduced, an adjustment to the system controller is also required. |
Sum of the installed maximum active power of all generation units of a system | ∑PEmax | Sum of the maximum active power of all inverters that are installed within a customer system (possibly in different buildings). |
Mixing system | - | Mixing systems in this context are systems in which a load and a generation unit are installed. |
Higher-level decoupling protection | üEKS | Protective features are required at the point of interconnection that disconnect the generating system from the utility grid when the voltage falls below or exceeds the permissible ranges during normal operation. The decoupling protection device measures at medium-voltage level and sends shutdown signals to the power generation system (PGS). |
Installed maximum apparent power of the generation unit | SEmax | Maximum AC apparent power (10 min average) of an inverter according to unit certificate as per VDE-AR-N 4110. Usually corresponds to the nominal power. |
Maximum apparent power of a generating system | SAmax | Highest 10-minute average of the apparent power of a generating system. |
Grid management service | GSM | Normative requirements (over 100 kW redispatch 2.0) to prevent grid bottlenecks as per § 9 of the Renewable Energy Sources Act (EEG). |
Direct marketers | DV | Direct selling is defined as being the sale of photovoltaic electricity to third parties through the utility grid. In practice, this is usually done via specialized direct sellers who either resell the electric current to large customers or trade it on the electricity exchange. |
Redispatch | RD | Measures for adapting the generating power to avoid grid overloads in specific grid segments. |
Frequency-sensitive active power adjustment | P(f) function | The P(f) function or P(f) characteristic curve describes an active power change depending on the grid frequency. In this context, a change in active power is described via a droop that results in a frequency exceeding 50.2 Hz and falling below 49.8 Hz. |
FGW Technical directive 3 | TR3 | The test standard FGW TR3 specifies the electrical properties of generation units and systems, storage systems and their components on the medium-, high- and extra-high voltage grid. |
Technical connections rules for the grid connection at all grid levels | TAR | A nationwide uniform set of rules that ensures the secure grid integration of renewable energies, interoperability of utility grids, and investment and planning security. |