The pilot of the experimental amateur-built airplane reported that he attempted to takeoff on a grass portion of his property, that extended about 1,000 ft prior to reaching powerlines. During takeoff on an approximate 130° heading, he noticed the airplane was not climbing fast enough to clear the powerlines. He pulled up "hard" to clear the powerlines but stalled the airplane. The left wing dipped down and the airplane impacted the ground. The right wing separated from the fuselage and the empennage was crushed behind the wings. Both main landing gear separated from the fuselage, and the nose gear folded back under the engine compartment. The pilot reported there were no preimpact mechanical malfunctions or anomalies that would have precluded normal operation of the airplane. He added that he thought the wind was swirling and may have encountered some windshear. The recorded wind at an airport located about 13 miles west of the accident site, about the time of the accident, was from 320° at 4 knots.