In this paper, the integration of a biomass-based diesel-wind system is investigated. The system consists of a pitch controlled wind turbine, which is equipped with an induction generator. The induction generator is connected to an ac bus-bar in parallel with a diesel-generator set consisting of a diesel engine driving a synchronous generator. A power plant can generate electric power using biomass from the olive tree in Spain. A gasifier is capable of converting tons of wood chips per day into a gaseous fuel that is fed into a diesel engine. While there are significant systems whose models may be exactly obtained from physical laws and whose states are measured, it is much less realistic to assume that all the parameters, such as the higher heating value of the biogas or wind speed, are exactly known. It is then natural to investigate what happens to control systems involving unknown, or not precisely known, parameters. In this paper, the derived model of biomass-based wind-diesel systems is quite valid for robust control studies.