An exergetic and exergoeconomic analyses of a power generation system based in biomass gasification in a downdraft gasifier and internal combustion engine, with surplus syngas accumulation in a storage tank in a non-interconnected zone (NIZ) in Colombia, has been made utilizing the Thermoflex software to obtain data of streams and properties and the EES software to solve the energy, exergy and exergoeconomic balances. The effect of gasifying temperature on the performance of the system has been studied as well as its effects on the cost of energy generated to the locality. The results obtained on irreversibilities, the cost of energy, and the exergoeconomic parameters are explained by graphs. for every hour of power demand in the locality selected. The results indicate that the accumulation of energy in the tank does not have a high rate of exergy destruction, but the discharge process does have a high value of irreversibilities or exergy destruction. According to the exergoeconomic balance, the weighted cost of energy is affected by the large irreversibilities in the accumulation of syngas in the tank, increasing this weighted cost as the gasification temperature is higher.