In this work, a framework for incorporating renewable energy sources into the economic dispatch problem of microgrid system is presented. It shows the possible advantages of adopting a predictive economic dispatch approach. In particular, simulation of the economic dispatch solution for a microgrid system -with both solar and wind technologies and also a battery storage system- illustrates the conditions under which the operation of power systems, with conventional economic dispatch algorithms do not provide a suitable solution. In addition, the purposed predictive strategy shows that it can leads to technical as well as economical improvements depending on the composition of the generation portfolio.