User profiling and micro-accounting for smart energy management

Energy management, and in particular its efficient optimization, is one of the hot trends in the current days, both at the enterprise level (optimization of whole corporate/government buildings) and single-citizens' homes. Energy efficiency is generally function of out-door techniques -- renewable energy, smart energy production and distribution, etc. -- and in-door techniques; in particular, very few energy managers -- each of us can be an energy manager of his own home - can state "who, when and why is consuming", conversely this knowledge is fundamental in order to diminish wasting of energy. Recent studies show that the energy wasted in the overall consumption is about the 30% of the total amount; examples of potential energy wasting are printers and PCs on during the night, status LED of different devices (TV, set-top-box, etc.) and/or lights, lights during normal day-light time, etc.