Directional solidification process is the main process for producing the multi-crystalline silicon ingots. It is economically beneficial to grow the good quality mc-Si ingots with lower power consumption. Here we have carried out numerical simualtion for analysing the impact of addition of an insulation block on the DS furnace. The addition of the insulation block has been implemented experimentally and the quality of the grown ingot was evaluated by the minority carrier lifetime measurement. Though the temperature gradient and hence the growth rate are higher in the insulation block added DS furnace, the generated dislocation density has not increased beyond the acceptable limit 10(8) 1/m(2). The power used by the DS furnace has been reduced considerably by the addition of the insulation block. The good quality mc-Si ingot with lower power consumption has been obtained as a result of insulation block addition.