The power consumption of Dynamically Reconfigurable Processing Array (DRPA) is quantitatively analyzed by using a real chip layout and applications taking into account the reconfiguration power. Evaluation result shows that processing power for PEs is dominant and reconfiguration power is about 20.7% of the total dynamic power consumption. Based on the above evaluation results, we proposed two dynamic power reduction techniques: functional unit-level operand isolation and selective context fetch. Evaluation results demonstrate that the functional unit-level operand isolation can reduce up to 20.8% of the dynamic power with only 2.2% area overhead. On the selective context fetch, the power reduction is limited by the increasing of the additional hardware.