Shortly after takeoff, the pilot discovered that the aircraft had suffered an electrical failure and he elected to return and land. On selecting the landing gear down, he advised that he felt the aircraft slow down and thought that the gear was extended. No gear position lights were available because of the electrical malfunction. During the landing flare the pilot realised that the aircraft was lower than normal, and applied full power in an attempt to go around. The aircraft settled onto the runway with the gear retracted before the power application was able to take effect. The reason for the electrical failure could not be determined. The pilot was unaware that, although the gear extension system is hydraulically actuated, the hydraulic pump is electrically operated and thus did not function following the electrical failure. This accident was not the subject of an on-site investigation.