Energy saving and environmental impact of small scale decentralized cogeneration deployment

In the last years many countries and international organizations have adopted several strategies in order to improve energetic and environmental behaviour of energy production and distribution systems. Many of these countries are attempting to use the same general purpose approach and many directives and standard, both at international and local levels, raised with the aim to reduce energetic consumption and pollutants production, as well as to protect human health and to minimize the impact on environment and the exploitation of the energy resources. Several actions are nowadays possible such as eco-efficiency, reduction and minimization of waste, use of technologies based on renewable sources, rationalization of the energetic production. Particularly, the reduction of energy consumption, or the improvement of energetic efficiency, involves economical advantages to the end users, gives benefits to the environment, contributes to the achievement of national and international targets about energy saving and environmental protection. Furthermore, the growing energy demand and the greenhouse gas emissions reduction, requires a wider application of technologies based on renewable sources and higher energetic efficiency. Among those technologies, the cogeneration, or the combined production of electric (and/or mechanical) and thermal energy starting from a primary energy source, is a well-established and up to date high efficiency technology, which leads to an environmental benefit and has been noted by the European Community as a key element to save primary energy, to avoid network losses and to reduce the greenhouse gas emissions. The cogeneration technology has been largely employed in industrial, tertiary and large building sectors but the recent availability of small size unit (< 15 electric kW) has led to a possible application at domestic and light commercial scale. The so called Micro combined Heat and Power, or MCHP for short, could represent an effective solution for improving energy efficiency to satisfy electrical, cooling and heating load demand for domestic users, reducing, as consequence of its higher efficiency, the related environmental impact. In this paper, starting from present MCHP's technologies available, an analysis on the energetic and environmental advantages derived from its diffusion has been carried out; it has been considered a domestic and hotel application with several levels of possible market penetration. The advantages of MCHP applications, also considering the Italian legislation, have been highlighted in terms of primary energy saving.