Understanding if a technologic solution satisfies the energy demands of a residential neighbourhood, and whether it is financially a benefit or not, cannot be determined by the only amount of energy that can be saved. Technologies such as CCHP could represent the perfect answer to this problem, on one condition though: it must be taken into consideration the reliability parameter as well. The plant configuration should guarantee a service without any interruptions. Redundancies must be evaluated and the consequences of the installation costs they imply. This study presents a method to make the right choice about an energy system characterized by: energy, reliability and economic services which satisfy power supplying to a polygeneration grid in a residential context. The case study is the area of Arci, near Rome, Italy. Our purpose is to realize a teleheating network and create a system able to satisfy the electric demands of the area. The first step is an accurate estimation of the electrical and thermal demands. Then we compare the optimized energy solutions with the traditional ones. Some changes have been introduced to improve the system's availability. All these steps take to an economic evaluation able to give some useful information about the feasibility of the technical choices previously made. (C) 2014 Elsevier B.V. All rights reserved.