Base load plants. These are plants which can take up load on the base portion of the load curve of the power system; they are generally of large capacity. run off river plants without pondage can be used as base load plants. Base load plants will be kept running practically on block load, i.e.,load that is practically cons-tant. plants having large storage can best be used as base-load plants,and particularly in rainy seasons,when the water level of the reservoir will be raised by rain water.the load factor of such plants is high.