What Happened to Dean Kamen's Stirling generator?

Nothing since 2014 (link:http://www.forbes.com/sites/christopherhelman/2014/07/02/dean-kamen-thinks-his-new-stirling-engine-could-power-the-world/2/

Like his ill-fated Segway, it appears his idea 9about the market) seem wrong. i recall reading about a similar attempt 15 years ago, it came to nothing. Stirling engines have been re-invented several times; yet, they never seem to deliver…why?

Wow. The guy who swung & missed with the Segway failed to make the Stirling engine into a profitable device. Go figure.

The hoverboard and electrified unicycle both seem to be making some headway in the world. The Segway itself was dumb, since it couldn’t compete with a bicycle, but the new inventions that are based on the same technology seem to be able to. Not that it does Kamen any good.

It has a low power-to-weight ratio rendering it more suitable for use in static installations where space and weight are not at a premium.
And therefore in practical use, inefficient.
Not the only reason its inefficient.

Being an EXTERNAL combustion engine, much of the heat from burning bypasses the cylinder and just goes away having done not a single thing.

At least with INTERNAL combustion engine, the combustion products are in the cylinder, and thus all the heat has gone into increasing pressure…

Yes the exhaust is quite hot… that heat could be reclaimed, but … Sterlin has been around for a while and it never ever got the go. Its no good for power stations, because its not smooth, its no good for small scale gen’s, because its gutless, its no use for transport, because its too heavy and the combustion isn’t sure to be stable… its useless.

Good on a lab bench for teaching or a curio …

His sales pitch is about using that excess heat for heating and hot water. He’s also touting the low cost of natural gas. Those things together may make it competitive with electric utilities in some markets. It would be very attractive to someone who wants to get off the electric grid but doesn’t mind staying on the gas grid. Is there anyone like that?

That makes no sense. All thermodynamic engines lose work potential due to exhaust heat, but this has nothing to do with external/internal combustion, and in fact Stirling engines are one of the most efficient cycles available.

You are right about the low power/weight ratio. That makes them unsuitable for most vehicles.

The main problem, as I see it, is that the economics don’t make sense for the home market. Internal combustion generators are cheaper for emergency use, where efficiency doesn’t matter. Off-grid people don’t want to be dependent on another energy source–exchanging electricity for natural gas isn’t really going off the grid. So they use solar and wind with battery backups. Who then is supposed to buy it?

A Stirling could make sense as a trickle charger for an electric car. A small one, maybe 20 horsepower, would be enough to keep the battery topped off. The battery handles the surges you need for acceleration and hills. The Stirling can have the long cycles it needs for maximum efficiency.