The pilot reported that he launched his hot air balloon for a brief solo flight with the intent of practicing maneuvers during calm wind conditions. Shortly after departure, he prepared for landing on a spot about 1/4-mile away that consisted of a flat harvested corn field. During the landing approach, he observed a powerline perpendicular to his final approach and landing target. He initially thought about climbing, but realized the balloon would not react fast enough, so he opened the vent to deflate the envelope and descend. The balloon envelope did not vent quickly enough and the balloon drifted into the powerlines, resulting in electrical arcing until the electrical breaker shut off. The basket settled onto the ground and the balloon envelope remained partially inflated and draped over the powerlines. The arcing resulted in substantial damage to the balloon; 6 cables were severed and there were multiple burn holes in the envelope. The pilot reported that there were no pre impact mechanical malfunctions or failures of the balloon that would have precluded normal operation or performance.