Today's European electricity grids have evolved over more than hundred years. The increasing penetration of renewable energy sources and other distributed sources in the energy supply in distribution grids leads to numerous technical challenges, which need a European approach. To cope with this, European pilot installations and field tests in research projects under the 5th framework programme as well as national projects have been carried out. They have analyzed real impacts of "connected" generators in a first step, and then have moved towards monitoring power quality, safety and reliability in "integrated" concepts, such as virtual power plants microgrids and active networks. The presentation shows different experiences with distributed generation and energy management systems in distribution grids in representative European pilot installations. It covers the aspects of power quality and safety, information and communication technologies and socio-economic aspects