Wind Project Performance 1994 Summary

2. WPRS Background

What Commission Efforts Led to the Wind Project Performance Reporting System?

The California Energy Commission (Commission) Wind Program was initiated in 1977 and later expanded in 1978 with the passage of California Assembly Bill 2976 authored by Assemblyman Henry Mello. The Mello bill required the Commission implement a state wind energy program to expedite the commercialization of utility-scale wind turbines. The Commission was responsible for: assessing wind resources throughout California; operating a public wind information center; testing wind-electric turbines; and conducting research to support development of large- scale prototype wind turbines.

When the industry began exponential growth in 1981, the Commission and the American Wind Energy Association (AWEA) recognized the need for performance and other technology-related information. Subsequent efforts by these two organizations led to adoption of Wind Project Performance Reporting System (WPRS) regulations in 1984.

What is the WPRS Program?

California law requires the California Energy Commission to serve as a central repository in state government for the collection and dissemination of information on energy supplies. Starting in January 1985, WPRS regulations required all California wind operators with projects rated at 100 kW or more to provide quarterly wind performance reports if they sold electricity to a power purchaser (utility). WPRS reports filed by operators include actual energy production and related project information. In addition, all California power purchasers are required to file quarterly reports documenting power purchases from wind operators. The Commission compiles and evaluates this data and documents findings in quarterly and annual reports on wind industry performance in California.

Why Were WPRS Regulations Developed?

WPRS regulations were instituted for several reasons. First, the industry, investors, financial community and government agencies needed actual performance data to better evaluate the status of wind technology. Second, information that would help minimize tax abuse would benefit everyone involved in wind development: the industry would generate less "bad press" and more favorable public opinion; investors would be better able to make informed investments; and government and public monies would be allocated to projects with optimal performance. WPRS regulations were intended to provide performance data useful for improved government tracking of energy supplies and better planning of the stateïs energy needs.

Before federal tax credits expired in 1985, project financing was primarily venture capital from private investors willing to take a substantial risk on the technology due to available tax benefits. Since the tax credits expired, wind projects have focused on revenues from power sales and placed greater reliance on conventional project financing from institutional lenders and foreign investors. WPRS data also are needed to establish performance credibility with these new sources of financing.

What Information Do WPRS Reports Provide?

The WPRS Annual Report includes the following information for all wind projects in California rated at 100 kilowatts (kW) or more that sell electricity to a power purchaser: turbine manufacturers, model numbers, rotor diameters and kW ratings; the number of cumulative and new turbines installed; the projected output per turbine; the output for each turbine model; and the output for the entire project. The WPRS Annual Report is compiled from quarterly reports submitted by project operators and public utilities. Commission staff use this WPRS data to analyze wind project performance and industry production and capacity trends. The Annual Report also contains data summary tables reflecting performance statewide and by resource area; turbine size, type and origin; manufacturer; and project operator. Note that totals expressed in tables and figures may not equal 100 percent due to rounding.

Since 1985, the Commission has documented and evaluated data submitted by operators and utilities in compliance with WPRS regulations. The extensive empirical data collected and disseminated by the Commission is used by industry, utility, investor, manufacturer, government, and research and development groups to measure the performance and relative benefits of wind technology.

What Information Is Not Found in WPRS Reports?

WPRS reports do not provide information on every wind energy project in California. Non-operating wind projects are not required to report to the Commission. The absence of a project from WPRS reports typically indicates that the project is not selling any power or is rated less than 100 kW. Other unreported capacity includes turbines that do not produce electricity for sale, such as turbines installed by utilities, government organizations and research facilities. Additional unreported capacity results when operators fail to file. Installed capacity for these operators cannot be confirmed and only kWh production verified from utility reports is included in WPRS reports.

WPRS reports cannot always account for the impact turbine age has on performance because turbines are often reported in groups combining old and new machines. To track improvements in technology, new turbine performance has been analyzed separately where possible.

The limited number of developers installing new capacity precluded adequate confidentiality of cost data. Therefore, aggregate cost data have not been included in the 1994 Annual Report.

What Limitations Should Be Considered Before Using WPRS Data?

Although many valuable observations about California's wind industry can be drawn from WPRS data, it is important to recognize four major limitations:

  1. While the Commission collects and reports WPRS wind data in annual reports, a complete industry evaluation requires consideration of collective data from several years. This is because the available wind resource varies from year to year depending on weather conditions.
  2. Much of the data reported is not directly comparable because the wind industry still does not employ a standardized turbine rating system. Turbines are tested under different conditions and rated at widely varying miles per hour specifications.
  3. Operator or manufacturer performance may not be accurately represented in the report when old and new turbine data are grouped together. Analysis of wind data reported since 1985 confirms that newer equipment typically performs more efficiently and reliably than older equipment.
  4. Performance data contained in WPRS reports do not reflect other important variables that should be considered. These variables include: cost per kilowatt, operation and maintenance costs, durability of the system, and quality of the site's wind resource.

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