Article Date:  February, 2000
                    Magazine Volume: 104
                       Issue: 2
                    Author(s): *Ann Chambers
                                          -

               Wind Power Spins Into Contention
 
               1999 was a banner year for the wind energy
               industry, and 2000 promises to be just as good
               if not better since the renewal of the wind
               energy tax credit near the end of 1999.
 
               Preliminary industry estimates show more than
               3,600 MW of wind generating capacity was
               installed last year, bringing total worldwide
               installed wind capacity to 13,400 MW. This total
               represents an increase of more than 36 percent
               over the 1998 total installed capacity of 9,751
               MW and the largest worldwide addition to wind
               capacity in a single year, according to American
               Wind Energy Association records.
 
               Between 1995 and 1998, 4,893 MW of wind
               capacity was installed worldwide for an average
               annual growth rate of 27.75 percent. Wind
               capacity has surged from less than 2,000 MW in
               1990 to 13,400 MW at the close of 1999.
 
               These statistics seem to support European
               Wind Energy Association claims that wind power
               can produce 10 percent of worldwide energy
               supply by 2020, even if electricity consumption
               increases substantially. Denmark and Germany's
               Schleswig-Holstein region are already
               approaching this 10 percent figure.
 
               "The 1990s have seen Europe emerge as a
               world leader in wind energy development, and
               we expect this strong performance to continue,"
               said Christophe Bourillon, EWEA executive
               director. "Our association has set targets for
               Europe alone of 40,000 MW of wind capacity by
               the year 2010 and 100,000 MW by the year
               2020."
 
               Bourillon attributes the surge in wind power's
               popularity to concern about climate change,
               worries about fossil fuel supplies, and the need
               to sustain an ever-increasing population. "Wind
               energy can reduce the amount of greenhouse
               gases released into the atmosphere, preserve
               valuable fossil fuel reserves for specialized uses
               and help poorer rural countries develop without
               resorting to polluting technology," Bourillon
               said. "Although there are uncertainties because
               of the changeable policy environment, we are
               projecting more than 5,000 MW of new growth
               in the United States over the next decade," said
               Randall Swisher, AWEA executive director.
 
               "Overall global investment in wind turbines
               should surpass $200 billion by 2010. The growth
               this past year is just the beginning of a rapid
               investment into renewable energy sources
               worldwide," said Michael Kujawa, senior Allied
               Business Intelligence Inc. analyst.
 
                

               The top three countries added 2,582 MW of new capacity and account for almost 64
               percent of total capacity additions in 1999. (See table.)
 
               Capacity Boom
               According to the AWEA's recently released
               "1999 Global Wind Energy Market Report," some
               732 MW of new wind capacity and an additional
               173 MW of repowering projects using new
               turbines to replace less efficient older machines
               were installed in the United States, bringing the
               nation's total capacity to approximately 2,400
               MW. 1999 saw wind capacity jump 40.8 percent
               over the previous year.
 
               An important catalyst to this unprecedented
               growth was the expiration of the wind energy
               production tax credit in June 1999. Developers
               raced to complete projects before the expiration
               deadline. The tax credit has since been
               retroactively reinstated and will run through
               Dec. 31, 2001. Wind energy producers can
               continue to receive inflation-adjusted 1.5
               cents/kWh tax credits for utility-scale projects.
               AWEA expects the continuing tax credit to spur
               more growth in the wind energy market.
 
               Other driving forces included progressive state
               policies, especially in Minnesota and Iowa, and
               the movement toward customer choice and
               green power programs in several states. Wind
               energy's relatively low cost has led more than
               80 utilities to offer a wind energy-based product
               to customers.
 
               "After struggling for most of the '90s, it (wind
               energy) has come of age at the very end of the
               millennium," states the AWEA report. "One
               reason for the limited activity in the mid-'90s
               was the uncertainty caused by deregulation of
               the electric sector, which caused many utilities
               to re-evaluate their priorities, and freeze any
               new investment in new capacity. In the
               meantime, wind technology has continued to
               mature, gradually convincing the electric
               industry that it is ready for broad deployment."
 
               The highest levels of development activity in
               the next few years are expected to be
               concentrated in the plains states and in Texas,
               which has mandated 2 GW of new renewable
               capacity in the coming decade. In the
               Northeastern region, restructuring legislation is
               opening the market to green power producers.
 
               Merchant Potential
               Enron Wind Corp. recently dedicated its Green
               Power I wind power facility near Palm Springs,
               Calif. The 22-turbine, 16.5 MW project was built
               solely to supply emerging green power markets
               and is the first major renewable power plant to
               enter California's market since it opened to
               competition in 1998.
 
                         

                         Green Power I began producing power in June 1999. Traditionally, wind power
                         has been sold only under long-term contract to utilities, however, the Green Power I
                         facility was built without contract and its power is being sold through retail marketers.
 
               The facility was developed, constructed and is
               operated by Enron Wind Corp. The project uses
               advanced Zond Z-750kW Series wind turbines.
               With 158 and 164 foot rotor diameters,
               approximately the size of the wingspan of a
               MD-11 jumbo jet, the Z-750kW wind turbines
               are the largest manufactured in the United
               States.
 
               New Technologies
               The U.S. Department of Energy has been
               working with the nation's wind turbine industry
               to improve technology and lower costs since
               1992. The first turbines created under these
               partnerships are already on the market, and a
               whole new generation of turbines is expected to
               arrive in 2002.
 
               Two new turbines are under development. In
               1994, DOE announced a $40 million program to
               develop a new generation of innovative utility
               wind turbines. The cost-effective turbines are
               expected to expand markets for U.S. companies
               in both the United States and in Europe, where
               competition for new wind projects is driving
               down costs.
 
               Eight industry teams created concepts for new
               utility wind turbines rated up to 1 MW. In 1996,
               the National Renewable Energy Laboratory
               selected two firms, Zond Energy Systems Inc.
               and The Wind Turbine Co., to move forward
               with their concepts.
 
               Zond, a subsidiary of Enron Wind Corp., is
               developing the A-56, which will probably be a 1
               MW machine. Its architecture has not yet been
               determined, but it may use a direct-drive
               generator alone or in combination with a
               conventional gearbox. Significant departures
               from conventional design are expected,
               including purpose-designed airfoils and
               low-solidity, flexible blades with individual pitch
               control. Taller, low-stiffness towers are
               expected, as are advanced control strategies to
               optimize energy capture and reduce loads.
 
               The Wind Turbine Co. is designing the WTC
               1000, a lightweight, two-bladed, downwind
               machine. The megawatt-scale turbine will
               include purpose-designed blades with individual
               pitch control, a variable coning rotor, highly
               integrated structure and drivetrain,
               load-mitigating control strategies, simplified
               fluid systems, and an extremely tall guyed
               tower. The WTC is targeted for applications in
               the Midwestern states.
 
               DOE is also working with three small turbine
               manufacturers, selected through competitive
               solicitation, to improve their turbines. The goal
               is to develop tested systems up to 40 kW in
               size that achieve a cost/performance ratio of 60
               cents/kWh at sites with annual average wind
               speeds of at least 12 miles per hour.
               Cost/performance ratio is defined as the initial
               capital cost of the turbine divided by its annual
               energy capture.
 
               Bergey Windpower Co. is working to improve
               cost/performance ratio for its BWC Excel 40 by
               designing a turbine with minimal maintenance
               requirements. The BWC Excel 40 is a 40 kW
               turbine targeted for battery charging in the
               village power market. It is a three-bladed,
               upwind, variable-speed machine with a
               direct-drive permanent-magnet alternator. Rotor
               blades will be pultruded fiberglass in three
               lengths for use in different wind regimes. The
               guyed lattice towers will be available in three
               heights. Projected cost/performance ratio is 38
               cents/kWh. DOE is funding $1.21 million of the
               research.
 
               WindLite Corp. is developing an 8 kW,
               variable-speed, direct-drive machine with a
               rotor diameter of 23 feet. The turbine uses a
               wound-rotor generator and proprietary controller
               that significantly increases its battery-charging
               efficiency compared to permanent-magnet
               generators. The projected cost/performance
               ratio for the WLC 7.5 is 46 cents/kWh. DOE is
               providing $1.43 million in funding.
 
               World Power Technology makes six small
               turbine models. Its Windfarmer, a 7 kW
               battery-charging wind turbine, is a
               three-bladed, upwind, variable-speed machine
               using a direct-drive, permanent-magnet
               generator. Fiberglass blades will be used on a
               16-foot diameter rotor. The machines will use a
               unique, patented angle-furling governor for
               protection in high winds. World Power is also
               developing a counter-weighted, tilt-down
               90-foot tower. Projected cost/performance ratio
               is 59 cents/kWh. DOE is providing $1.25 million
               in funding.
 
               Big Spring Keeps on Turning
               As early as 1993, TXU Electric and Gas
               investigated the level of demand for renewable
               energy in Texas. Encouraged by the enthusiasm
               of its customers toward green energy, TXU
               unveiled plans for the $40 million Big Spring
               wind power project near Midland in December
               1998. Developed by York Research, the project
               has 46 turbines with a total capacity of 34 MW.
               The final phase, completed in April 1999, saw
               the commissioning of the largest commercial
               wind turbines in the world-four Vestas V66
               turbines standing approximately 260 feet tall
               above the elevated plateau of west Texas ranch
               land.
 
               TXU believes that the project is testament to
               the fact that as power technologies advance,
               electricity generated by renewable resources
               will become more common and economic.
 
               The Big Spring project is built on mesas, rising
               195 to 295 feet above the surrounding areas.
               The winds accelerate as the move up over these
               mesas. Annual average hub-height wind speeds
               range from 18.4 to 22.2 mph over the site.
 
               There are three phases to the site. Phase I has
               16 Vestas V47 660 kW turbines, Phase II has
               26 Vestas V47s, and Phase III has the four
               Vestas V66 1,650 kW turbines.
 
               Projected annual electricity generation for Big
               Spring is 117 million kWh.
 
                       

               Both turbine models use three rotor blades of epoxy and fiberglass composite.
               Crosswind separation of the machines is nominally 3.5 rotor diameters.  Row-to-row
               spacing of the machines exceeds 10 rotor diameters to minimize the impact of
               turbulence from adjacent rotors.
 
               The turbine control system monitors turbine
               starts and stops under normal operating
               conditions and also protects the turbines under
               extreme emergency conditions such as faults
               caused by a loss of grid load while under power
               or a component failure. In addition, the system
               manages the power output of each turbine by
               pitching the blades and changing the generator
               slip to maximize energy production while
               minimizing loads at wind speeds greater than
               31 mph.
 
               The control system is operated by a digital
               computer using Vestas-developed programs.
               Portions of the system are located in the base
               of the tower and in the nacelle of the wind
               turbine. These are linked by fiber optic lines to
               minimize interference and damage from
               lightning.
 
               A key feature of the control system is OptiSlip,
               which controls loads and spikes from the
               turbines under high wind speeds. OptiSlip
               allows the turbine to operate in a similar way to
               a variable speed machine, preventing the drive
               line of the machine from experiencing torque
               spikes.