In this study, the ultimate aim is to provide objective scientific proof to promote biodiesel blends in constant areas (official institutions, hospital, school, etc.) as a renewable fuel. For that, biodiesel obtained from animal, vegetable and microalgae oil by a method of transesterification and these biodiesels have been prepared by 10% blended with diesel fuel and has been named respectively as AB10, VB10 and MB10. The biodiesel blends and reference diesel fuel (ULSD) have compared with by obtained combustion and emission values in a diesel engine generator system under cold start, loadless and high idling constant engine speed of 1500 rpm. Experimental results showed that using biodiesel blends in diesel engine generator system had almost parallel cylinder gas pressure (CGP), cumulative heat release (CHR), heat release rate (HRR), knock density (KD) and mean gas temperature (MGT) compared to ULSD fuel operation in this research diesel engine. In addition, CO, NOx and HC emissions decreased, CO2 increased compared to ULSD fuel at same experimental conditions.