WindUnion calls for 'warning strike' at Siemens Gamesa's German offshore wind turbine factoryStrike also to affect Prysmian unit as metal workers' union increases pressure in collective bargaining for higher wages in metals and electronic industriesSiemens Gamesa's offshore wind turbine factory in Cuxhaven, GermanyPhoto: RechargeBernd RadowitzEuropean Editor, Recharge