Due to the adverse impacts of the consumption of fossil fuels on our environment, the quest for a more sustainable energy supply is increasingly intensifying. Many renewable energy sources, such as wind, solar and tidal power generate electricity. Therefore, the development towards a sustainable energy supply leads to increasing electrification. Generators and consumers of electricity are connected by electricity networks. Traditionally, electricity networks transport electrical power from controllable bulk power generators running on fossil fuels or uranium to consumers. However, the combination of decentralization of generation, caused by the smaller scale of renewable generators, and decreasing controllability, caused by the fact that the availability of renewable energy sources is determined by the weather and can hardly or not be affected, requires new functions of electricity networks, in particular of distribution grids. The decreasing degree of controllability of electricity production and the high, but rare peaks caused by embedded generation require involving consumption in balancing supply and demand. To this end, electricity networks must develop towards a "Smart Grid". One of the consequences of this trend is a need for a whole new category of communication, measurement and control equipment. In the paper, first the background of the development towards Smart Grids will be studied in more detail. Then, architectural considerations are discussed and an overview of telecommunication technologies for application in the electricity grid and in the home is presented.