TITLE:
Sustainability of Wind Energy under Changing Wind Regimes—A Case Study
AUTHORS:
Nicole Mölders, Dinah Khordakova, Ralph Dlugi, Gerhard Kramm
KEYWORDS:
Sustainability of Wind Energy, Sensitivity of Wind Energy to Decadal Climate Variations, CESM, Downscaling, Interannual Variability
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.6 No.2,
March
1,
2016
ABSTRACT: A method
was introduced to assess the sustainability of energy production over the
lifetime (~20 y) of wind turbines. Community Earth System Model simulations
were downscaled for the tourist seasons (mid-May to mid-September) of 2006 to
2012 (CESM-P1) and 2026 to 2032 (CESM-P2) to obtain a reference and projected
wind-speed climatology, respectively. The wind speeds served to calculate the
potential power output and capacity factors of seven turbine types. CESM-P1
wind-speed climatology, power output, and capacity factors were compared to
those derived from wind speeds obtained by numerical weather forecasts for
reference to known standard to wind-farm managers. Juneau, Alaska served as a
virtual testbed as this region is known to experience changes in wind speeds in
response to the Pacific Decadal Oscillation. CESM-P2 suggested about 2%
decrease for wind speeds between the speeds at cut-in and rated power, and
about 8% - 10% decrease in potential wind-power output. This means that in
regions of decadal climate variations, the sustainability of wind-energy
production should be part of the decision-making process. The study
demonstrated that using mean values of wind-speeds can provide qualitative
knowledge about decreases/increases in potential energy production, but not
about the magnitude. Using the total individual wind-speed data of all seasons
provided the same amount of total power output than summing up the power
outputs of individual seasons. The main advantage of calculating individual
seasonal wind-power outputs, however, is that it theoretically permits assessment
of interannual variability in power output and capacity factors. Comparison to
a known standard may help stakeholders in understanding of uncertainty and interpretation
of projected changes.