Globalattentionhasturnedtorenewableenergysources,suchassolarenergyandwindpower,astheenvironmentalandsus-tainabilityproblemsassociatedwiththeongoinguseofcoalandoilasprimaryenergysourcesarefinallybeingacknowl-edged.TheChinesegovernmentrecentlylaunchedtwomajorPVprojectssimultaneously,andwindpower,whichcouldverypos-siblybecomethethirdmajormodeofenergygeneration,afterthermalandhydropower,isalsobeingrapidlydeveloped.Renewableenergypowersystemsincorporateapower-generatingcomponent,anenergystoragecomponent,andtherequisitecontrolcircuitry.PVpowersystems,forexample,com-prisesolarcellmodules,batterypacks,andacontroller.Thesolarcellmodulesconvertsolarenergyintoelectricpowerduringtheday,someofwhichisprovidedtothedc/acloads,theremaindertochargethebatterypacks.Thebatterypacksmustsupplypowertothedc/acloadwhenthesunisinaccessible,orthecellsrequiremaintenance,andshouldalsobeabletoprovidealargemomentarycurrentinordertostartequipmentsuchaselectricmotors.Investi-gationsofpreviouslyconstructedPVpowerstationshaverevealedthatthestoragebatterieswereinevitablyoneofthemajorreasonsforPVpowerstationoperatingproblems[