Hundreds of environmental activists are set to protest the expansion of US electric carmaker Tesla’s factory outside of Berlin on Sunday. Production at the giant factory was halted on Tuesday after a suspected arson attack on the power supply by a left-wing extremist group. Authorities say electricity could still be days away from being restored. Protest organizers say they have no connection to the power failure, which also affected thousands of local residents. Sunday’s rally is to demand that leaders in the small town of Grünheide, located in an area known for its forests and lakes, abide b…