The consumption of electrical energy by future cars is predicted to be in the range of several kW, exceeding that of today's cars approximately. four-fold, even in the case of mid sized vehicles. To save fuel, new components and systems are under development, which will replace mechanical and hydraulic power by electrical power. The advantage of the new systems is that they consume power only in the case they are utilised. Some of them will be safety relevant. Additionally, comfort and convenience of future cars will be further increased. Most features are to be expected to be realised via electrical power. As a result, the complexity of vehicle electrical systems will be significantly increased. Two main measures will help to solve the issues: the development and implementation of an effective power management and the introduction of a new 42 V level. The paper gives an overview of the most important aspects of a modem energy management and explains intentions and values of the new 42 V draft standard. (C) 2001 Elsevier Science B.V. All rights reserved.