For several years it has been discussed controversially, whether the ＇＇Least-Cost Planning ＇＇ - developed in the USA and increasingly described as ＇＇Integrated Resource Planning＇＇ -will be a suitable management and control concept for the German electricity economy. In this article the discussion is presented and structured, as well as the central questions are explained. Decisive aspects are thereby the questions, how to deal with ＇＇Least-Cost Planning ＇＇ in the range of control, as well as the role which ＇＇Least-Cost Planning ＇＇ should play in respect of internalization of extreme costs.