Agence France-Presse: German engineering giant Siemens said Friday it has won one of its biggest ever renewable energy contracts, worth more than two billion euros (2.5 billion dollars) for wind turbines. “The agreement with Dong Energy (of Denmark) is one of the biggest orders in the history of Siemens,” a statement quoted the head of Siemens’ renewable energy division Rene Umlauft as saying. Siemens will to deliver up to 500 offshore turbines from 2011 to the Danish power company, a spokeswoman …