This book provides unspecialized decision-makers, citizens, students and policy-makers of the future with significant information about a dynamic sector: energy - and a space: city - that are both critical for sustainability. Progress towards sustainable development is impossible without the active participation of informed and aware citizens and decision-makers. Cities and the energy field are now on the verge of dramatic changes. Immediate change is difficult and innovation is crucial if inefficient patterns are to be transformed into intelligent systems.