Tritium ignited by powerful lasers within a magnetic containment "bottle". This is going on at Lawrence Livermore Labrotories in California. The electricity used is enormous and the magnetic field generated is milllions of time as powerful as Earth's natural magnetic field. It is, however, shielded and tightly focused. The tritium pellet is slightly larger than the head of a pin.

IF they can get this to work it will pay back the electricity thousands of times over in clean, non-polluting energy with helium and some hydrogen as a by-product.

Least-wise, that's how I remember it!