Wind Power Generation Trends
Publication Number: CEC-500-2005-181
Publication Date: DECEMBER 2005
PIER Program Area: Renewable Energy Technologies
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Introduction
The importance of wind energy has long been recognized by the California Energy Commission (ENERGY COMMISSION), which supports research and development in renewable energy including wind through its Public Interest Energy Research (PIER) Program. Wind energy provides significant benefits in terms of improved air quality, increased diversity in electric energy sources, local and state revenues, and employment. Still, wind energy development in California faces a large number of minor and major impediments.
In an effort to foster additional development of wind energy in the state, the ENERGY COMMISSION created the California Wind Energy Consortium (CWEC), which is managed by the University of California at Davis. The mission statement of the California Wind Energy Consortium (the Consortium) is to support the development of safe, reliable, environmentally sound, and affordable wind electric generation capacity within the state of California. To fulfill this mission, the Consortium will manage a focused, statewide program of scientific research, technology development and deployment, and technical training. The effort is conducted in close cooperation with industry, state and federal agencies, and other institutions to maximize the benefits of wind energy resources in California for its citizens.
Wind Turbine Generator Optimization
One of the Consortium’s first assignments was a series of white papers, whose purpose was to review the performance of wind turbines in typical operating environments. Wind turbine power generation characteristics are affected by a wide range of factors including: seasonal changes in air density, blade soiling (insect debris, dust, etc.), control system interactions with turbulent winds, maintenance procedures, and connection issues to the electrical transmission system. These factors impact both the cost and the value of wind power production. The goal of this effort is to evaluate performance issues and identify methods and procedures for maximizing wind energy generation and value.
Three topic areas were identified for the white papers:
- Daily wind power generation trends
- Optimization of wind turbine peak capacities
- Transmission interconnection issues and standards
This report includes data evaluations, commentary, and review in the first two topic areas. The goal of this effort was to establish a sense for the variations in wind power generation in California and assess the change in these levels according to the time of day and the season of the year. Representative wind data was obtained and adjusted to standard air density. This data was then used to determine the power output of three representative 1 MW wind turbines with different rotor sizes: 50 meter diameter, 70 m diameter, and 90 meter diameter. The output from these turbines was compared against the statewide system electrical demand and trends were observed.
Abstract
This report includes data evaluations, commentary, and review of daily wind power generation trends an d optimization of wind turbine peak capacities in California. The goal of this effort was to establish a sense for the variations in wind power generation in California and assess the change in these levels according to the time of day and the season of the year. Representative wind data was obtained and adjusted to standard air density. This data was then used to determine the power output of three representative 1 MW wind turbines with different rotor sizes: 50 meter diameter, 70 m diameter, and 90 meter diameter. The output from these turbines was compared against the statewide system electrical demand and trends were observed.
Table of Contents
1.0 INTRODUCTION 11.2 Wind Turbine Generator Optimization 1
2.2 Turbine Performance Model 4
3.2 Diurnal Generation Patterns 11
3.3 Statewide Power Demand 13
3.4 Peak Demand Periods 16
3.5 Diurnal Marginal Capacity 21
4.2 Wind Generation Revenue 24
5.2 Recommendations 27
LIST OF TABLES
Table 2.2 Specific Power of Model Wind Turbines 5
Table 2.3 Blade Planform Definition 6
Table 2.4 Summary of Rotor Non-Dimensional Performance 7
Table 2.5 Summary of Turbine Rotor Properties 7
Table 2.6 Drive Train Efficiency Model 8
Table 2.7 Turbine Power Output as a Function of Wind Speed 8
Table 2.8 Turbine Capacity Factor as a Function of Wind Speed 11
Table 3.1 Top Ten Peak Demand Days of 2001 17
Table 4.1 Summary of Average Annual TDV Revenue Factors 26
Table 4.2 Comparison of Constant Value and TDV Revenue Factors 26
LIST OF FIGURES
Figure 2.2 Specific Power as a Function of Rated Power for Existing Turbines and Model Turbines 5
Figure 2.3 Blade Planform Drawing 6
Figure 2.4 Turbine Power Curve Comparison 8
Figure 3.1 First Quarter 2001 Power Generation at the 7 m/s Site 10
Figure 3.2 Second Quarter 2001 Power Generation at the 7 m/s Site 10
Figure 3.3 Third Quarter 2001 Power Generation at the 7 m/s Site 10
Figure 3.4 Fourth Quarter 2001 Power Generation at the 7 m/s Site 10
Figure 3.5 Turbine Average Annual Capacity Factor as a Function of Wind Speed and Rotor Diameter 11
Figure 3.6 March, April, November, and December Daily Capacity Factor for the 70 m Turbine and 7 m/s Wind Speed 12
Figure 3.7 January, February, September, and October Daily Capacity Factor for the 70 m Turbine and 7 m/s Wind Speed 12
Figure 3.8 May, June, July, and August Daily Capacity Factor for the 70 m Turbine and 7 m/s Wind Speed 13
Figure 3.9 First Quarter 2001 Power Demand 14
Figure 3.10 Second Quarter 2001 Power Demand 14
Figure 3.11 Third Quarter 2001 Power Demand 14
Figure 3.12 Fourth Quarter 2001 Power Demand 14
Figure 3.13 First Quarter 2001 Average Daily Demand Factor 15
Figure 3.14 Second Quarter 2001 Average Daily Demand 15
Figure 3.15 Third Quarter 2001 Average Daily Demand 16
Figure 3.16 Fourth Quarter 2001 Average Daily Demand 16
Figure 3.17 Turbine Capacity and Statewide Demand During a Summer Peak Period at the 6 m/s Reference Site 17
Figure 3.18 Turbine Capacity and Statewide Demand During a Summer Peak Period at the 7 m/s Reference Site 17
Figure 3.19 Turbine Capacity and Statewide Demand During a Summer Peak Period at the 8 m/s Reference Site 18
Figure 3.20 Turbine Capacity and Statewide Demand During a Summer Non-Peak Period at the 6 m/s Reference Site 18
Figure 3.21 Turbine Capacity and Statewide Demand During a Summer Non-Peak Period at the 7 m/s Reference Site 18
Figure 3.22 Turbine Capacity and Statewide Demand During a Summer Non-Peak Period at the 8 m/s Reference Site 19
Figure 3.23 Average Capacity Factor as a Function of Demand Factor at the 6 m/s Reference Site 19
Figure 3.24 Average Capacity Factor as a Function of Demand Factor at the 7 m/s Reference Site 19
Figure 3.25 Average Capacity Factor as a Function of Demand Factor at the 8 m/s Reference Site 20
Figure 3.26 Average Capacity Factor as a Function of Demand Factor for the 7 m/s Reference Site 20
Figure 3.26 First Quarter 2001 Marginal Capacity of the 70 m Turbine at the 7 m/s Reference Site 21
Figure 3.27 Second Quarter 2001 Marginal Capacity of the 70 m Turbine at the 7 m/s Reference Site 21
Figure 3.28 Third Quarter 2001 Marginal Capacity of the 70 m Turbine at the 7 m/s Reference Site 22
Figure 3.29 Fourth Quarter 2001 Marginal Capacity of the 70 m Turbine at the 7 m/s Reference Site 22
Figure 3.30 Comparison of August 2001 Marginal Capacity at the 7 m/s Reference Site 23
Figure 4.1 Mojave Commercial Electricity Value Factor 24
Figure 4.2 Capacity Factor and Electricity Value Factor During a Summer Peak Period at the 7 m/s Reference Site 24
Figure 4.3 Revenue Factor and Capacity Factor During a Summer Peak Period at the 7 m/s Reference Site 25
Figure 4.4 Revenue Factor and Capacity Factor During a Summer Non-Peak Period at the 7 m/s Reference Site 25