Calculating Load Factors

AmunSession.run_load_factor_for_parameters(flow_parameters: aurora.amun.client.parameters.FlowParameters, base_parameters: aurora.amun.client.parameters.LoadFactorBaseParameters)

Calculate the load factor and wind speeds for a year given a start time and a location.

See also

AmunSession.get_region_details() to get region codes and available datasets for a point

Parameters
Returns

A Dictionary with the keys

  • parameters

  • appliedParams

  • typicalHourly

  • weatherYearHourly

Return type

Dictionary

from aurora.amun.client.session import AmunSession
session  = AmunSession()

base_parameters = LoadFactorBaseParameters(
   turbineModelId=6,
   latitude=59.59,
   longitude=0,
   startTimeUTC="2018-01-01T00:00:00.00Z",
   regionCode="GBR",
   hubHeight=90,
   obstacleHeight=0,
   lossesAvailability=0.1,
   numberOfTurbines=12,
   roughnessLength=0.02,
   usePowerCurveSmoothing=False,
 )

 flow_parameters = WeibullParameters(measurementHeight=90, weibullScale=12, weibullShape=6)

 load_factors = session.run_load_factor_for_parameters(
   flow_parameters, base_parameters
 )

Common Parameters

class LoadFactorBaseParameters(turbineModelId: int, latitude: float, longitude: float, startTimeUTC: str, regionCode: str, hubHeight: float, obstacleHeight: float, numberOfTurbines: int, roughnessLength: float = None, usePowerCurveSmoothing: bool = None, smoothingCoefficient: float = None, lossesWake: float = 0.0, lossesAvailability: float = 0.0, lossesElectrical: float = 0.0, lossesTurbinePerformance: float = 0.0, lossesEnvironmental: float = 0.0, lossesOtherCurtailment: float = 0.0)

Parameters for all wind types.

Note

Not all regions/locations support Multi-Turbine Power Curve Smoothing.

Parameters

  • turbineModelId (int) – The Id of the Turbine to use in the calculation as returned from AmunSession.get_turbines().

  • latitude (float) – The latitude of the point (-90 to 90).

  • longitude (float) – The latitude of the point (-180 to 180).

  • startTimeUTC (str) – The time in UTC that the calcution should start from. This must be in the form ‘2016-07-28T00:00:00.000Z’ .

  • regionCode (str) – The code for the region used to set region specific parameters.

  • hubHeight (float) – Given in meters (m).

  • obstacleHeight (float) – Given in meters (m).

  • numberOfTurbines (int) – The number of turbines in the site.

  • roughnessLength (float, optional) – Static roughness. If not given, will be derived from reanalysis data. Defaults to None.

  • usePowerCurveSmoothing (bool, optional) – Should Default Multi-Turbine Power Curve Smoothing be used in the calculation if true then a region specific scale factor is used. If None then no smoothing is applied Defaults to None.

  • smoothingCoefficient (float) – The value to use for smoothing. This will override any region specific values. This has no effect unless usePowerCurveSmoothing is true.

  • lossesWake (float) – The percentage to apply for wake loss. (0 <= lossesWake < 1)

  • lossesAvailability (float) – Percentage for external losses. (0 <= lossesAvailability < 1)

  • lossesElectrical (float) – Percentage for external losses. (0 <= lossesElectrical < 1)

  • lossesTurbinePerformance (float) – Percentage for external losses. (0 <= lossesTurbinePerformance < 1)

  • lossesEnvironmental (float) – Percentage for external losses. (0 <= lossesEnvironmental < 1)

  • lossesOtherCurtailment (float) – Percentage for external losses. (0 <= lossesOtherCurtailment < 1)

Flow Based Parameters

class BuiltInWindParameters(windType: aurora.amun.client.parameters.WindType, useReanalysisCorrection: bool = None, reanalysisScaleCorrectionDelta: float = None)

The parameters used for built in wind calculations.

Note

Not all locations support all wind types and not all locations support Regional Reanalysis Correction.

Parameters

  • windType (WindType) – one of (WindType.Era5,WindType.Merra2,WindType.NEWA)

  • useReanalysisCorrection (bool, optional) – Should Regional Reanalysis Correction be enabled. If true then a location

  • reanalysisScaleCorrectionDelta is used. Defaults to None. (specific) –

  • reanalysisScaleCorrectionDelta (float, optional) – Override the location specific reanalysisScaleCorrectionDelta.

  • has no effect if reanalysisScaleCorrectionDelta is false. Defaults to None. (This) –

class WeibullParameters(weibullShape: float, weibullScale: float, measurementHeight: float)

The parameters required for a Weibull calculation.

Parameters

  • weibullShape (float) – The long term shape parameter from your wind report

  • weibullScale (float) – The long term scale parameter from your wind report

  • measurementHeight (float) – The height at which the measurements were taken (m)

class AverageWindSpeedParameters(averageWindSpeed: float, measurementHeight: float)

The parameters required for a AverageWindSpeed calculation.

Parameters

  • averageWindSpeed (float) – The average wind speed of your site to use as calibration (m/s)

  • measurementHeight (float) – The height at which the measurements were taken (m)

class PowerDensityParameters(averagePowerDensity: float, measurementHeight: float)

The parameters required for a PowerDensity calculation.

Parameters

  • averagePowerDensity (float) – The average power density of your site to use as calibration (W/m2)

  • measurementHeight (float) – The height at which the measurements were taken (m)

class UploadedWindParameters(uploadedWindStartTime: str, lowHeight: aurora.amun.client.parameters.SpeedAtHeight, highHeight: aurora.amun.client.parameters.SpeedAtHeight = None, granularityInMins: int = 60)

The parameters required to run a custom (uploaded) load factor calculation. If highHeight is specified it must be the same length as the lowHeight and be measured at a greater height. The speeds upload should be hourly measurements starting at uploadedWindStartTime and span at least 1 year.

Parameters

  • uploadedWindStartTime (str) – The time in UTC that the wind speeds upload start from. This must be in the form ‘2016-07-28T00:00:00.000Z’ .

  • lowHeight (SpeedAtHeight) – The height and speed for the low height wind speed to upload.

  • highHeight (SpeedAtHeight, optional) – The height and speed for the high height wind speed to upload. Defaults to None.

class P50ScalingParameters(p50GrossProduction: float)

The parameters required for a P50Scaling calculation.

Parameters

p50GrossProduction (float, 0 < p50GrossProduction < 1) – the P50 load factor which represents the long-term production potential of this site, typically from an energy assessment report, will be used to calibrate the underlying reanalysis wind speed, such that the long-term production potential used in Amun-based valuations are the same.

class P50YieldScalingParameters(annualProductionInGWHours: float)

The parameters required for a P50YieldScaling calculation.

Parameters

annualProductionInGWHours (float, 0 < annualProductionInGWHours < 1000000) – the production expected by the site in a year in Gigawatt Hours.