This paper shows a practice to raise the reliability of an electric power system by the
installation of distributed generation, taking gasified biomass as fuel. To calculate the reliability index,
a probabilistic load flow was used. This index is determined as the fault probability of the system.
The resolution of this probabilistic load flow combines the method of cumulants and Gram–Charlier
expansion. To achieve the reliability index, simulating a number of contingencies is required; the
greater the number of simulated contingencies, the higher the accuracy of the index obtained. This
probabilistic technique uses the random variables as starting information, so the two generators
and loads are simulated as random variables. The generators of this distributed generation are
biomass-fueled gas engines, commonly found in Spain. The simulations carried out on the IEEE
14-bus Test System, including three biomass generators, show that the inclusion of this type of
generation improves the overall reliability indices of the electrical syste
