Steorn hasn’t said that their technology taps ZPE. They don’t explain why it works, just that it does — and they say that it can do useful work.
Sorry for the mix-up. But it doesn't matter. My point is: Either the Orbo is some kind of perpetuum mobile (there have been countless designs, be it purely mechanical or using electrical parts), then it doesn't work because of the
law of conservation of energy. Or it claims to harness some kind of exotic form of energy. Given that e.g. to harness fusion power you need a $15 billion, 100 feet high machine, it is highly unlikely that you can do that with a bit of plastic and a few wires. Bluntly speaking: It's a scam, get over it.
I will gladly - to quote Jeremy Clarkson - eat my hair if I'm wrong. But I'm not. You want to believe, that's your right and choice. But there are better things to believe in, e.g. cheap solar power or nuclear fusion, because they actually have a chance of working out in the long run.