The twin-engined aircraft took off from Kerry Airport at 08.30 hrs on an IFR flight to Jersey. Soon after take-off, the aircraft lost all onboard electrical power, communications and weather radar. The Pilot initially flew the aircraft South and subsequently made an approach to Cork Airport from the sea. The undercarriage was lowered manually. Power was suddenly restored and, after confirmation from ATC that the undercarriage gear was locked down, the pilot landed the aircraft safely.