Ongoing changes in the operation of distribution grids call for a new way to plan grid modifications. This presentation gives an overview of possible methods of long-term planning for the deployment of Distributed Energy Resources (distributed generation, storage and controllable loads) in a given grid. The placement and sizing of the units have to be considered, making this a complex optimization problem with discrete and continuous variables. In the optimization problem, multiple objectives are often conflicting, e.g. minimal grid losses, maximal use of the resources and voltage stability. An evolutionary algorithm (genetic algorithms) is used to search for fit topologies of distributed resources and analyze the possible trade-offs. Combining the objectives with weight factors to a total cost leads to an inefficient solution. It is more appropriate to include Pareto front analysis. As an extension, when CHP is involved, gas grid distribution expansions planning and the DER placement problem have to be considered together. When dispatchable generation units or storage elements are taken into account, a control algorithm has to be derived as well. Additionally the introduction of DER in a house "grid" will be discussed. This is a particular case of the planning problem. Though in this case, a local DC grid may be an (energy-efficient?) alternative option. The specific advantages and disadvantages of this technology will be treated briefly.