Glossary

AWES Performance Definitions

TermDefinitionExplanationSymbol
Cycle Power / Electrical Average Poweenergy over one power divided by the time.It should be measured on the AWES side, i.e. before the transformer.A cycle is mainly relevant for ground-generation systems.Most important is the electrical power.The following graphs explain this term: Measured at the output of the individual system, before the transformer.(Definition for conventional wind turbines: Measured on the low voltage side of the transformer, i.e. it is measured on the turbine side.)TBD how to define for off-grid systems that are only connected to a battery pack.Pe,avg
Rated power / Nominal power / power Power at the Rated Wind SpeedThe nominal power is the red dot in the figure above.This metric is the one that would be compared with a conventional wind turbine (e.g. “2 MW-turbine).oPn
Electrical peak power during reel-outPeak power- measured at the system side (just before feeding it from a single system into the park)- measured at the system side of the transformer (park towards grid). Maximum power that a system can sustain over a certain time before failures are very likely. [kW]Measured after the generator. To be differentiated: Peak power after the generator. Peak power that goes into the grid – this is important for the grid operator. Some measures may be applied so that peaks are avoided.It depends on the rated power of the electrical machine.If you go above this value for extended period of times, the generator may get hot or something may break.But the peak power at the transformer could be lowered through heat elements (resistor banks) or storage devices.Graph with the different system componentsand where measurement points would be (suggestion by Joep, see also notes at end of the document):


TT: Should focus here on the relevant value from a grid operator perspective or what is the critical value to size the grid connection. Might be important to specify values for different durations (1s peak vs. 30s peak for example).
Pe,o,peak
Electrical peak power during reel-inPeak power measured during reel-in. [kW]Power (measured at several points, tbd), should be measured where relevant to capacitythat needs to be contracted.Pe,i,peak
Produced energy during reel-outEnergy generated by the system during reel-out phase (where applicable). [kWh]“Internal” term, not so relevant for AWE clients.

The produced energy is always equal or larger than zero.
Ee,o
Consumed power during reel-inPower consumed by the system during reel-in phase (where applicable). Measured in kWh.“Internal” term, not so relevant for AWE clients.

The consumed power / energy sign convention does not follow the traditional sign convention e.g. the calculation of the mechanical consumed power as tether speed times (positive tether speed is reel out speed) tetherforce requires taking the absolute value to align with the sign convention.

Consider that with a battery there would be no power needed from the grid.Important to determine efficiency of the system and size of the generator.Tbd if instantaneous or averageTT: Should talk about energy in kWh, power is specified in P4.
Ee,i
Annual Electricity Production (AEP)The yearly Error: Reference source not foundError: Reference source not foundenergy production of a facility.Calculated as produced energy minus the consumed energy. [MWh/a]Measured AEP vs. Calculated AEP.We may have to define a standard site to allowcomparison between systems or versions of systems. Also difference between single systems and parks (wake effects, etc.)
Rated wind speed nd speed at which the AWES produces the rated power outputDefinition adapted to IEC 61400-1 "minimum wind speed at hub height at 100m which a wind turbine's rated power is achieved in the case of steady wind without turbulence." Default: when not explicitly stated when referring to wind speeds, one can assume it refers to the rated wind speed.
One point on the power curve.