One of the big problems though is shown in this thread... Most people are just calling "con", if it is actually real how does he get people to take notice? [..]
Of a cheap, very compact, non-polluting, non-radioactive scalable power source that actually works? It's true that most people will assume it's a con, but if it's actually real then he has a massive advantage - it would actually work.
A vehicle would do the job well. There are competitions for alternative fuel cars. It wouldn't have to be a good car, so you wouldn't need any significant knowledge about cars. It's just about getting your boxes to power something with wheels that moves. Drive it 500 miles without emissions or recharging. Round and round a track would do the job for that. People will pay attention to a car that has been driven 500 miles without emissions, refueling or recharging. Offer to demonstrate it working.
Use it to power your house. When your electricity and gas bills are zero, it won't be long before the power companies start investigating. They will of course assume that you are fiddling the meters. Tell them to feel free to take it to court - you can prove you have no need of their electricity or gas. That court case gives you an offiical forum for demonstrating your device.
Essentially, show it as a potential product.
There are plenty of people who'll believe complete cobblers when it comes to alternative energy sources. It should be possible to convince some less gullible people by virtue of having a device that actually works and work upwards from there.