I would imagine he meant energy of a million tonnes of TNT. Since the speed of light is approximately 300,000,000m/s, a particle of 1 gram travelling at 1/4 the speed of light has a kinetic energy of 5,625,000,000,000 Joules (i.e. 15,625,000kWh or enough energy to run a 100W lightbulb for 1782...