Given pressing climate challenges such as global warming, air pollution, and pressure on natural resources, greening energy is at the very forefront of the political agenda. The energy sector and its regulation in the European Union, its member states, and indeed in the world in general, are therefore undergoing significant innovation and change. Energy innovations include a transition from fossil fuels to more renewable energy sources, increasing energy efficiency, removing CO2 emissions via storage and the development of new technologies in general. In this connection it is a question how technology can be applied or developed to achieve the ultimate target of reducing CO2 emissions. In this connection smart cities are increasingly gathering attention. An urbanization with a population shift from rural to urban areas, is occuring and is going hand -in-hand with a higher emphasis on mitigation of climate change. What are the goals and what changes are necessary in the future supply and consumption of fuels and energy if it is to live up to the mantra of becoming ‘smart’? Focus will address the shift towards a more intelligent and sustainable society improving the way people may live in cities, getting more out of limited resources, using energy more efficiently, and making cities as attractive as possible for citizens and businesses. It includes equipping the city’s facilities and infrastructure with sensors to measure everything from air quality, parking, drinking water, electricity grid, sewage systems, and traffic to the content of the garbage container. Smart grids and energy systems may be identified as a key enablers for a future low-carbon electricity system, facilitating demand-side efficiency, increasing the shares of renewables and distributed generation, and enabling electrification of transport. However, the application of intelligent technology and the data that is gathered may pose major challenges to citizens’ fundamental rights. Moreover, one may speculate about whether or not it is possible to limit how the intelligent tools can be used or misused and who the smartness is providing benefits for.