Renewable Energy Handbook 2010 - Department of Finance - The ...

A 1.1.4 SPECIFIC CONSIDERATIONSWind speed varies considerably with height aboveground, and is affected by local environmentalconditions. Practical wind turbines are designed towork between certain wind speeds. The lower speed,called the ‘cut in speed’, is generally 4-5m per secondas there is insuffi cient energy below this speed toovercome system losses.OFFICE OF ENERGYRENEWABLE ENERGY HANDBOOK 201047RENEWABLE ENERGY BACKGROUNDRENEWABLE ENERGY ATLAS OF AUSTRALIA:Mean Wind Speed at 80m above ground levelDarwinBrisbaneMetres per Second5.65.86.06.16.26.36.46.56.66.76.97.07.27.810Figure 10.Mean Wind Speedat 80m aboveground level.SOURCE:RENEWABLE ENERGYATLAS, DEPARTMENTENVIRONMENT, WATER,HERITAGE AND THE ARTS.Perthwww.environment.gov.au/renewable/atlas0 250 500 1,000KilometresAdelaideSydneyCanberraMelbourneHobartData Sources:Capital Cities© Commonwealth of Australia (Departmentof the Environment, Water, Heritage andthe Arts) 2008State Borders© Commonwealth of Australia (GeoscienceAustralia) 2008Wind Speed© Windlab Systems Pty Ltd 2007Caveat:All data are presumed to be correct asreceived from data providers. Noresponsiblility is taken by theCommonwealth for errors or omissions.The Commonwealth does not acceptresponsibility in respect to anyinformation or advice given in relationto, or as a consequence of anythingcontained herein.Map produced by:Environmental Resources InformationNewtork (ERIN), Department of theEnvironment, Water, Heritage and theArts, October 2008.Albers Equal-Area Projection (GDA94)Another consideration is that much of rural WesternAustralia has limited capacity power lines that arenot suitable for commercial, utility-scale wind farmswithout an upgrade.Wind turbines can also present challenges for systemmanagement especially during low load periodsovernight, which are characteristic of the South WestInterconnected System. As load reduces in the evening,generation plants would normally be taken out ofservice to be restarted as load rises the followingmorning. Only the minimum required plant continuesoperation overnight – typically the most costefficient plant to run, but often also the least fl exible.Wind generators, which have very low operating costs,effectively compete with those generators that wouldotherwise have operated over this period.Complicating the management of low overnight loadsis the fact that conventional generators have a minimumoutput below which they cannot maintain stableoperation and that wind turbines require a level ofconventional generation support to securely managethe variability of wind generator output on the electricitysystem. Together these factors can require the operationof a more costly fl exible plant overnight to support windgeneration and the overnight shutdown of a minimum costplant that would otherwise have operated continuously.Finding a technically secure and economically effi cientresponse to this challenge is a matter receiving closeattention both here in WA and elsewhere in the world,as the contribution of wind generation grows.The North Country Reinforcement project (NCR) willcontribute to addressing this issue. The NCR consistsof a 330 kilovolt transmission line from the Pinjarsubstation, just north of Perth, to a new terminalat Moonyoonooka, just outside Geraldton. There area number of wind farms proposed for the Mid WestRegion and the NCR Project may allow some of theseto proceed. In July 2009, Stage One of the NCRproject was approved extending the 330 kilovoltpower transmission line from Pinjar to Eneabba.