Without independent measurements it could be several things:

1) A hoax as the energy is supplied by an external source to heat up the device... essentially a new light bulb.
2) An exothermic (heat creating) chemical reaction... even if not cold fusion it might be worthwhile depending on the cost (monetary and energy required) to create the device
3) Cold fusion... maybe. Although the oil companies might be against it (we still need plastics). The scientific community would love to see this.

Note that we have working fusion in labs. However the net amount of energy is negative... we can fuse atoms, just the energy we make is less then we put in. Fission (splitting atoms) could be much more widely available and would make an ideal base load provider whilst creating minimum waste. With the intermittent power supplies (wind, water, sunlight) we can solve a lot of these issues with better batteries and/or capacitors (not just electrical but mechanical ones ... like the London Bridge has).