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Title: Assessing variability of wind speed: comparison and validation of 27 methodologies

Abstract

Abstract. Because wind resources vary from year to year, the intermonthly and interannual variability (IAV) of wind speed is a key component of the overall uncertainty in the wind resource assessment process, thereby creating challenges for wind farm operators and owners. We present a critical assessment of several common approaches for calculating variability by applying each of the methods to the same 37-year monthly wind-speed and energy-production time series to highlight the differences between these methods. We then assess the accuracy of the variability calculations by correlating the wind-speed variability estimates to the variabilities of actual wind farm energy production. We recommend the robust coefficient of variation (RCoV) for systematically estimating variability, and we underscore its advantages as well as the importance of using a statistically robust and resistant method. Using normalized spread metrics, including RCoV, high variability of monthly mean wind speeds at a location effectively denotes strong fluctuations of monthly total energy generation, and vice versa. Meanwhile, the wind-speed IAVs computed with annual-mean data fail to adequately represent energy-production IAVs of wind farms. Lastly, we find that estimates of energy-generation variability require 10 ± 3 years of monthly mean wind-speed records to achieve a 90% statistical confidence. This papermore » also provides guidance on the spatial distribution of wind-speed RCoV.« less

Authors:
; ; ORCiD logo
Publication Date:
Research Org.:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind and Water Technologies Office (EE-4W)
OSTI Identifier:
1480875
Alternate Identifier(s):
OSTI ID: 1481842
Report Number(s):
NREL/JA-5000-72768
Journal ID: ISSN 2366-7451
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Published Article
Journal Name:
Wind Energy Science (Online)
Additional Journal Information:
Journal Name: Wind Energy Science (Online) Journal Volume: 3 Journal Issue: 2; Journal ID: ISSN 2366-7451
Publisher:
European Wind Energy Association - Copernicus
Country of Publication:
Germany
Language:
English
Subject:
17 WIND ENERGY; inter-annual variability; statistics; uncertainty quantification; variability; wind resource assessment

Citation Formats

Lee, Joseph C. Y., Fields, M. Jason, and Lundquist, Julie K. Assessing variability of wind speed: comparison and validation of 27 methodologies. Germany: N. p., 2018. Web. doi:10.5194/wes-3-845-2018.
Lee, Joseph C. Y., Fields, M. Jason, & Lundquist, Julie K. Assessing variability of wind speed: comparison and validation of 27 methodologies. Germany. https://doi.org/10.5194/wes-3-845-2018
Lee, Joseph C. Y., Fields, M. Jason, and Lundquist, Julie K. Mon . "Assessing variability of wind speed: comparison and validation of 27 methodologies". Germany. https://doi.org/10.5194/wes-3-845-2018.
@article{osti_1480875,
title = {Assessing variability of wind speed: comparison and validation of 27 methodologies},
author = {Lee, Joseph C. Y. and Fields, M. Jason and Lundquist, Julie K.},
abstractNote = {Abstract. Because wind resources vary from year to year, the intermonthly and interannual variability (IAV) of wind speed is a key component of the overall uncertainty in the wind resource assessment process, thereby creating challenges for wind farm operators and owners. We present a critical assessment of several common approaches for calculating variability by applying each of the methods to the same 37-year monthly wind-speed and energy-production time series to highlight the differences between these methods. We then assess the accuracy of the variability calculations by correlating the wind-speed variability estimates to the variabilities of actual wind farm energy production. We recommend the robust coefficient of variation (RCoV) for systematically estimating variability, and we underscore its advantages as well as the importance of using a statistically robust and resistant method. Using normalized spread metrics, including RCoV, high variability of monthly mean wind speeds at a location effectively denotes strong fluctuations of monthly total energy generation, and vice versa. Meanwhile, the wind-speed IAVs computed with annual-mean data fail to adequately represent energy-production IAVs of wind farms. Lastly, we find that estimates of energy-generation variability require 10 ± 3 years of monthly mean wind-speed records to achieve a 90% statistical confidence. This paper also provides guidance on the spatial distribution of wind-speed RCoV.},
doi = {10.5194/wes-3-845-2018},
journal = {Wind Energy Science (Online)},
number = 2,
volume = 3,
place = {Germany},
year = {Mon Nov 05 00:00:00 EST 2018},
month = {Mon Nov 05 00:00:00 EST 2018}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.5194/wes-3-845-2018

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Works referenced in this record:

Using reanalysis data to quantify extreme wind power generation statistics: A 33 year case study in Great Britain
journal, March 2015


Geographical and seasonal variability of the global “practical” wind resources
journal, December 2013


Annual and seasonal variations in mean wind speed and wind turbine energy production
journal, January 1990


Wind Resource Assessment
book, May 2012


Inter-annual variability of wind indices across Europe
journal, January 2006

  • Pryor, S. C.; Barthelmie, R. J.; Schoof, J. T.
  • Wind Energy, Vol. 9, Issue 1-2
  • DOI: 10.1002/we.178

Determining variabilities of non-Gaussian wind-speed distributions using different metrics and timescales
journal, June 2018


Year-to-year correlation, record length, and overconfidence in wind resource assessment
journal, January 2016

  • Bodini, Nicola; Lundquist, Julie K.; Zardi, Dino
  • Wind Energy Science, Vol. 1, Issue 2
  • DOI: 10.5194/wes-1-115-2016

Interannual Variability and Seasonal Predictability of Wind and Solar Resources
journal, July 2017


Quantifying the variability of wind energy: Quantifying the variability of wind energy
journal, November 2013

  • Watson, Simon
  • Wiley Interdisciplinary Reviews: Energy and Environment, Vol. 3, Issue 4
  • DOI: 10.1002/wene.95

Characterization of wind power resource in the United States
journal, January 2012


What can reanalysis data tell us about wind power?
journal, November 2015


Climate change impacts on wind energy: A review
journal, January 2010


The impact of climate change on the levelised cost of wind energy
journal, February 2017


European wind variability over 140 yr
journal, January 2013

  • Bett, P. E.; Thornton, H. E.; Clark, R. T.
  • Advances in Science and Research, Vol. 10, Issue 1
  • DOI: 10.5194/asr-10-51-2013

Climate and climate variability of the wind power resources in the Great Lakes region of the United States
journal, January 2010

  • Li, X.; Zhong, S.; Bian, X.
  • Journal of Geophysical Research, Vol. 115, Issue D18
  • DOI: 10.1029/2009JD013415

Effects of climate oscillations on wind resource variability in the United States
journal, January 2015

  • Hamlington, B. D.; Hamlington, P. E.; Collins, S. G.
  • Geophysical Research Letters, Vol. 42, Issue 1
  • DOI: 10.1002/2014GL062370

Variability of the Wind Turbine Power Curve
journal, September 2016


Uncertainty in recent near-surface wind speed trends: a global reanalysis intercomparison
journal, November 2017

  • Torralba, Verónica; Doblas-Reyes, Francisco J.; Gonzalez-Reviriego, Nube
  • Environmental Research Letters, Vol. 12, Issue 11
  • DOI: 10.1088/1748-9326/aa8a58

The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)
journal, July 2017


Rainfall Seasonality: Description, Spatial Patterns and Change Through time
journal, July 1981


Wind speed trends over China: quantifying the magnitude and assessing causality: WIND SPEED TRENDS OVER CHINA
journal, December 2012

  • Chen, L.; Li, D.; Pryor, S. C.
  • International Journal of Climatology, Vol. 33, Issue 11
  • DOI: 10.1002/joc.3613

Understanding Biases in Pre-Construction Estimates
journal, June 2018


The ERA-Interim reanalysis: configuration and performance of the data assimilation system
journal, April 2011

  • Dee, D. P.; Uppala, S. M.; Simmons, A. J.
  • Quarterly Journal of the Royal Meteorological Society, Vol. 137, Issue 656
  • DOI: 10.1002/qj.828

Quantifying sources of uncertainty in reanalysis derived wind speed
journal, August 2016


Persistence of low wind speed conditions and implications for wind power variability: Persistence of low wind speeds
journal, May 2012

  • Leahy, Paul G.; McKeogh, Eamon J.
  • Wind Energy, Vol. 16, Issue 4
  • DOI: 10.1002/we.1509

Wind speed trends over the contiguous United States
journal, January 2009

  • Pryor, S. C.; Barthelmie, R. J.; Young, D. T.
  • Journal of Geophysical Research, Vol. 114, Issue D14
  • DOI: 10.1029/2008JD011416

Uncertainty Analysis in MCP-Based Wind Resource Assessment and Energy Production Estimation
journal, July 2008

  • Lackner, Matthew A.; Rogers, Anthony L.; Manwell, James F.
  • Journal of Solar Energy Engineering, Vol. 130, Issue 3
  • DOI: 10.1115/1.2931499