That's a great concern, but I don't think we're talking about requiring an exemplar to patent so much as a "use it or lose it" system. And "use" doesn't have t

That's a great concern, but I don't think we're talking about requiring an exemplar to patent so much as a "use it or lose it" system. And "use" doesn't have to mean implement. In your case, you'd just tell the truth: "I've been making a good-faith effort to license this generator technology to power companies, but they keep turning me down because they're waiting for my patent to expire instead so they get it for free." If you can document that effort, there's no reason we couldn't consider that a valid use and sustain the patent— and so the power companies have no incentive not to license your technology, and so the generator gets built and everyone wins. Remember also that the only case this comes up in is if a power company sues you to get your technology for free on the grounds that you aren't using it. If you offered to sell it to them first, that's a pretty open and shut case.