Long Term Hub-Height Wind Speed

This script demonstrates one possible approach to calculating a long term hub-height time series.

Hub-height time series covering the on-site measurement period are re-scaled to match a user-entered long-term monthly wind speed profile, then rescaled such that they have an overall wind speed matching a long-term hub-height wind speed predicted in the calculate wind climate task in the UI.

/// <summary>
/// Predicts the long term hub height wind speed time series needed to run the power time series calculation
/// A LTHHWS time series is generated for every set of wind climate data used to initiate turbines
/// 
/// Process:
/// 1. Get the relevant hub height time series, as calculated in the Hub height time series task with "hhts" in the name
/// 2. Speedup HHTS by month to using a target monthly wind speed profile
/// 3. Scale the monthly-scaled HHTS to the long term mean wind speed on the initiating wind climate data 
/// 
/// Resulting series are saved as calculated signals with the identifier LTHHWS{0}m
/// </summary>
public void Execute()
{
	// USER INPUT:
	
	// Specify the target monthly wind speed profile, representing the monthly wind speed to be applied at each site
	List<double> longTermMonthlyWindSpeedProfile = new List<double>{
		9.9, 10.1, 9.9, 8.8, 8.8, 9.9, 10.1, 9.9, 8.8, 10.2, 7.8, 5.6
	};
	
	// END OF USER INPUTS
	
	Toolbox.Log("Predicting monthly profile re-scaled long term hub height wind speed time series for power time series inputs");
	MeasurementCampaignToolbox mc = Toolbox.MeasurementCampaign;
	
	// Suppress word reports being generated
	bool suppressReportingStatus = Toolbox.MeasurementCampaign.SuppressReporting;
	Toolbox.MeasurementCampaign.SuppressReporting = true;
	
	// Iterate through all the wind climates used to initiate flow models
	List<Tuple<MeasurementSite, WindClimate>> initiationMastAndWindClimates = GetAllInitiatingMastsAndWindClimates();
	
	foreach (Tuple<MeasurementSite, WindClimate> mastAndWindClimate in initiationMastAndWindClimates)
	{
		MeasurementSite mast = mastAndWindClimate.Item1;
		WindClimate hubHeightWindClimate = mastAndWindClimate.Item2;
		double height = hubHeightWindClimate.HeightAboveGroundLevel;
		
		// Get the hub height time series, calculated in the Hub height time series task with hhts in the name
		string hubHeightSignalName = mast.CalculatedSignals.Where(s =>s.SignalName.ToLower().Contains("hhts")&& s.HeightAboveGround == height).Select(x => x.SignalName).FirstOrDefault();
		SpeedTimeSeries hubHeightTimeSeries = mc.GetSpeedTimeSeries(hubHeightSignalName);
		Toolbox.Log(string.Format("Generating a long-term hub height time series corresponding to {0} at {1}m", hubHeightTimeSeries.Name, height));
		// Speedup HHTS by month to using the target monthly wind speed profile
		List<double> longTermMonthlyMeanSpeeds = longTermMonthlyWindSpeedProfile;
		List<double> measurementMonthlyMeanSpeeds = mc.GenerateStatistics(hubHeightTimeSeries).CalendarMonthStatistics.Select(m => m.Mean).ToList();
		List<double> monthlyScaleFactors = elementWiseArrayDivision(longTermMonthlyMeanSpeeds, measurementMonthlyMeanSpeeds);
		SpeedTimeSeries monthlyScaledHubHeightTimeSeries = (SpeedTimeSeries)mc.SpeedUpSeriesByMonth((TimeSeries)hubHeightTimeSeries, monthlyScaleFactors, Enumerable.Repeat(0.0, 12).ToList());
		monthlyScaledHubHeightTimeSeries.Name = hubHeightTimeSeries.Name + "_monthlySpedUp";
		Toolbox.Log("\t Sped up time series by month");
		
		// Scale the monthly-scaled HHTS to the long term mean wind speed found of the initiating wind climate data 
		double targetLongTermHubHeightWindSpeed = hubHeightWindClimate.FrequencyDistribution.MeanWindSpeed;
		double currentmeanSpeed = mc.GenerateStatistics(monthlyScaledHubHeightTimeSeries).AnnualOrOverall;
		double rescalingFactor = targetLongTermHubHeightWindSpeed / currentmeanSpeed;
		SpeedTimeSeries longTermHubHeightTimeSeries = mc.SpeedUpSeries(monthlyScaledHubHeightTimeSeries,  rescalingFactor );
		
		// Save resulting series with the identifier LTHHWS{0}m
		mc.SaveResultsTimeSeries(longTermHubHeightTimeSeries, mast, string.Format("LTHHWS{0}m", height.ToString()), height, true);
		Toolbox.Log(string.Format("\t Saved long term hub height wind speed time series {0} to mast {1}", longTermHubHeightTimeSeries.Name, mast.Name ));
	}
	Toolbox.MeasurementCampaign.SuppressReporting = suppressReportingStatus;
	Toolbox.Log("Complete");
}


/// <summary>
/// Find the initiating data used in the flow model for every turbine
/// </summary>
/// <returns>A list of initiating MeasurementSite - WindClimate tuples</returns>
public List<Tuple<MeasurementSite, WindClimate>> GetAllInitiatingMastsAndWindClimates()
{
	List<Tuple<MeasurementSite, WindClimate>> initiationMastAndWindClimates = new List<Tuple<MeasurementSite, WindClimate>>();
	
	// get a list of all masts and wind climate which actually initiate turbines - these are the ones we need LTHHTS for
	foreach (WindFarm windFarm in Workbook.WindFarms)
	{
		foreach(Turbine turbine in windFarm.Turbines)
		{
			FlowModel turbineFlowModel = Workbook.Climate.FlowModels.GetAtLocation(turbine.HubHeightLocation);
			MeasurementSite initiationMast = turbineFlowModel.ReferenceMeasurementSite;
			WindClimate initiatingWindClimate = turbineFlowModel.ReferenceWindClimate;
			
			if (false == initiationMastAndWindClimates.Select(t => t.Item2).Contains(initiatingWindClimate))
			{
				initiationMastAndWindClimates.Add(
					new Tuple<MeasurementSite, WindClimate>(initiationMast, initiatingWindClimate));
			}
			//Toolbox.Log(string.Format("Turbine {0} uses initiation mast {1} wind climate {2} at height {3}", turbine.Name, initiationMast.Name, initiatingWindClimate.FrequencyDistribution.Name, initiatingWindClimate.HeightAboveGroundLevel));
		}
		string report = "Found the following wind climate data initiating turbines:";
		foreach (Tuple<MeasurementSite, WindClimate> mastAndWindClimate in initiationMastAndWindClimates)
		{
			report += string.Format("\n\tMast {0} uses wind climate FD {1}", mastAndWindClimate.Item1.Name, mastAndWindClimate.Item2.FrequencyDistribution.Name);
		}
		Toolbox.Log(report);
	}
	return initiationMastAndWindClimates;
}


public List<double> elementWiseArrayDivision (List<double> numerator, List<double> denominator)
{
	if( numerator.Count!= denominator.Count)
	{
		throw new Exception("Numerator and demoninator lists are of non-equal lengths");
	}
	
	List<double> result = numerator.Select((val, index) => val / denominator[index]).ToList();
	return result;
}