The European Union recently established an ambitious target by 2020 that consists of increasing the utilization of renewable energy up to 20%, reducing its overall pollutant emissions by at least 20%, and achieving a primary energy saving of 20% compared to reported 1990 levels. This aim can only be realized with strong effort in different sectors, such as residential, commercial, industry, tertiary, transportation. In particular in the European Union, a remarkable contribution to energy consumption and CO2 emissions is concentrated in residential and commercial sector. The introduction of more efficient technologies in these sectors could help in achieving the results expected by 2020. An option is given by cogeneration, defined as the combined "production" of electric and/or mechanical and thermal energy starting from single energy source. This technology could be considered one of the first elements to save primary energy, to avoid network losses and to reduce greenhouse gas emissions. In particular, this article focuses on the microcogeneration (electric powers <= 15 kW), which represents a valid and interesting application for residential and light commercial users. The energy, economic and environmental implications due to the use of small scale cogeneration systems were reported, by means of an experimental research activity performed by the authors and other researchers. (C) 2010 Elsevier B.V. All rights reserved.