California Wind Energy Resource Modeling and Measurement
Publication Number: CEC-500-2006-062
Publication Date: June 2006
PIER Program Area: Renewable Energy Research
The executive summary, abstract and table of contents for this report are available below. This publication is available as an Adobe Acrobat Portable Document Format File. In order to download, read and print PDF files, you will need a copy of the free Acrobat Reader software installed in and configured for your computer. The software can be downloaded from Adobe Systems Incorporated's website.
Download APPENDIX 3: Final Detailed Measurement Program Plan in Acrobat PDF ( 13 pages, 112 kilobytes )
Download APPENDIX 4: Final Boundary Layer Research and Findings Report in Acrobat PDF ( 26 pages, 892 kilobytes )
Download APPENDIX 5: Final Statewide Wind Maps and Modifications Report in Acrobat PDF ( 6 pages, 19.2 megabytes - Note size! )
Executive Summary
This project carried out several recommendations from a previous California Energy Commission (Commission) project entitled “New Wind Energy Resource Maps of California,” Contract #500-01-009. That project developed the current statewide wind map and recommended research that could lead to improvements in the accuracy of the wind map. Three recommended areas of research were: (1) increase the resolution of the model runs in selected focus areas; (2) improve modeling capabilities of the atmospheric boundary layer; and (3) measure the winds at heights relevant to modern turbines, using tall towers and sodar systems, to provide research and validation data for the first two recommendations.
The objective of this project is to improve the accuracy of wind resource estimates in several promising wind development areas of California through advanced measurement, modeling, and mapping. The project consisted of five technical tasks:
- Selection of Focus Areas
- Focused High-Resolution Wind Mapping
- Measurement Program
- Boundary Layer Modeling Research
- Adjustments to the Statewide Wind Maps.
Following a screening process that considered over twenty candidate areas, five focus areas were identified: Mojave Desert, San Gorgonio Pass, Tehachapi Pass/Antelope Valley, the Mayacamas Mountains, and Shasta Valley. High-resolution wind mapping was conducted for the focus areas, with a final mesoscale resolution of 1 km and microscale resolution of 100 m, twice the resolution used to produce the current statewide wind map. The higher resolution model runs revealed that modest adjustments to the statewide wind map are in order within the focus areas because of the improved resolution of influential terrain features. The Measurement Program consisted of one-year of data collection at four tall towers at heights well above industry-standard meteorological masts, plus seven short-term sodar campaigns that measured wind profiles up to heights of 200 m. The boundary layer modeling research identified three key factors affecting simulation accuracy and took steps to better resolve these factors.
The principal benefits of the project to the State of California are:
- Enhanced wind map accuracy within promising wind energy development areas
- New measurement database at modern turbine heights covering 11 sites
- Improved boundary layer modeling and prediction capabilities.
These benefits will help improve the siting of future wind plants, yield more accurate energy production predictions for proposed projects, and enhance the skill of the scheduling and forecasting of next-hour and next-day wind plant outputs for commissioned projects. It is recommended that other focus areas of the state be investigated through new measurement and modeling initiatives to improve the understanding of their wind regimes. This will broaden wind energy development opportunities in California.
Abstract
This report presents the results of a project designed to improve the accuracy of wind resource estimates through advanced measurement, modeling, and mapping applications in several promising wind development areas of California. Five focus areas were identified: the Mojave Desert, San Gorgonio Pass, Tehachapi Pass/Antelope Valley, the Mayacamas Mountains, and Shasta Valley. For each area, high-resolution wind mapping simulations were run at twice the resolution of the existing statewide wind map, revealing modest adjustments to the intensity and structure of the local wind resource. A campaign of yearlong tall tower wind measurements and short-term sodar measurements was also implemented. These data supplied inputs to a boundary layer modeling research task intended to resolve key simulation problems. A modified statewide wind map was produced. Recommendations are given to expand new measurement and modeling initiatives to other areas of the state having development promise.
Keywords: Wind map, wind measurement, tall-tower, sodar, boundary layer modeling
Table of Contents
Abstract iiiPreface iv
Executive Summary v
1.0 Introduction 1
1.2 Project Objectives 2
1.3 Outline of Report Organization 2
2.2 Focused Wind Mapping 7
2.3 Measurement Program 7
2.3.2 Sodar Campaign 8
2.5 Adjustments to the Statewide Wind Maps 8
3.2 Focused Wind Mapping 10
3.2.2 San Gorgonio Pass 10
3.2.3 Tehachapi Pass and Antelope Valley 11
3.2.4 Mayacamas Mountains 11
3.2.5 Shasta Valley 11
3.3.2 Sodar Campaign 12
3.4.2 Terrain Complexity 14
3.4.3 Surface Energy Budget Formulation 14
4.2 Commercialization Potential 18
4.3 Recommendations 18
4.4 Benefits to California 19
List of Figures
Figure 1: Overview of Focus Areas as well as Tall Tower and sodar locations Tall Tower and reference station locations 6
Figure 2: Comparison of 2002 and 2006 wind speed maps for Focus Area D 15
Figure 3: Comparison of 2002 and 2006 wind power density maps for Focus Area D 16
List of Tables
Table 1: Tall Tower long-term wind speed projections 12