The development of the power supply systems necessary for the feed-in of renewable energies brings energy supply and information and communication technologies closer together. Power supply systems are converted into intelligent energy information networks that will not only transport energy in the future but also data about consumption and availability. In smart cities, households and energy suppliers exchange data that is transparent to the consumer and thereby supports conscious power consumption. Intelligent electric meters, so called smart meters, are already in use today and allow the consumers to flexibly arrange their power consumption according to the rate.

The increase in renewable energies will cause larger fluctuations of supply and demand for power generation, which will in turn influence the price. With the help of smart metering, consumers can see when supply is high and price is low, so that they can adjust their energy consumption accordingly. When electricity is low priced they can for example turn on the washing machine or charge the electric car by means of applications that constantly adjust supply to personal needs. Therefore, intelligent power consumption does not only promote a more conscious handling of resources but also a sustainable improvement to the carbon footprint.

The reduction of energy consumption and one’s carbon footprint are important issues in smart cities. Sustainability during the development of smart cities can be best illustrated using the example of energy consumption. At this point, structures are created that will last a long time and can be characterized by their adaptability to changing conditions. Just like the new communication networks, the energy infrastructure will no longer be statically oriented to a supply format but will instead be flexible. The adaptable new communication and supply infrastructure leads to a dynamic in the smart city that aims for the highest possible efficiency and sustainability. Aside from the development of power supply systems in smart cities, buildings are being insulated city-wide and energy-saving construction types such as passive houses are promoted for new constructions.

The promotion of alternative energy supply systems and the regionalization of power generation lead to greater competition which will provide many consumers with independence and significant savings if they are able to use energy more efficiently and to generate energy themselves. By feeding-in self-generated, excess electricity into the intelligent, Europe-wide networked power supply system, private households become in essence energy producers. Just as in the area of communication, the energy sector is getting an evolutionary push forward. With the involvement of citizens and regional businesses, the resulting transformation from passive consumer to active partner and even energy producer is being realized.