From 2000 to 2014, the energy infrastructure of the city of Hamburg was mainly in the hands of private energy monopolies such as Vattenfall and E.On that controlled most of Germany's electric power infrastructure. These companies had a strong interest in utilizing their coal and nuclear power plants as long as possible, thereby obstructing a shift to renewable energy. Moreover, they were reluctant to provide equal access to small power providers and invest in a smart grid that allows more effective management of variable, distributed power inputs.