Inventor's clues fuel talk that ideal engine is near

Gareth Cook / Boston Globe 7mar01

New Hampshire inventor Dean Kamen, who sparked worldwide excitement in January when word leaked of his mysterious new invention, code named ''Ginger,'' appears to be working on a revolutionary engine that could introduce an era of cheap, efficient power.

Investigative journalist Adam Pennenberg, author of a book on industrial espionage, said yesterday that he has found clues that prove Kamen is working on a Stirling engine, a device that engineers have been trying to perfect for more than a century.

In November, Kamen's company registered the Web site name ''stirlingengine.com,'' said Pennenberg, who describes the results of an investigation into Kamen in the next issue of Inside magazine.

If Kamen, a well-respected inventor, has made a technical breakthrough that would allow him to create small, relatively inexpensive Stirling engines, engineers said, the effects would be far-reaching. In theory, every home could generate its own cheap power with a device the size of an air conditioner that uses natural gas, drastically cutting down on the waste inherent in the electric grid.

An advanced Stirling engine could have wide applications and could literally change how humans use power - bringing its inventor incredible riches.

''If you can release a product that makes the electric grid obsolete, that would change industry and the world,'' said Brent Van Arsdale, who reviewed a patent Kamen holds on a Stirling engine improvement, and who is the president of American Stirling, a company that uses model Stirling engines as an educational tool. The patent and the ''stirlingengine.com'' name, Van Arsdale said, suggest that the mysterious Ginger invention is a Stirling engine, possibly used to power a scooter.

Stirling engines have been the focus of enormous effort, and many inventors have thought for a time that they were close to a major breakthrough. But the engines can be extremely complex, and nobody believes that Kamen has solved all the technical problems that stand between an inventor and a workable Stirling that is reliable, safe, inexpensive, and easy to manufacture. Kamen, however, has an impressive track record - including a National Medal of Technology.

The Inside magazine article reports that Kamen has created a company called ACROS that plans to make ''motorized, self-propelled, wheeled personal mobility aides, namely wheelchairs, scooters, carts, and chariots.'' Kamen has also registered the domain names ''stirlingscooter.com,'' ''stirlingscooter.net,'' ''stirlingscooter.org,'' and ''mystirlingscooter.com,'' according to the article.

Stirling engines run on heat, which can be created by any fuel, and rely on a design that differs from the ubiquitous internal-combustion engine. The engines' design can make them extremely fuel-efficient and very clean-running, features that have long attracted engineers. But Stirling engines can also be expensive, slow to warm up, and hard to operate at different speeds.

Stirling engines are already used to create power in remote locations, but in the past they have been too expensive to be used in most homes, Van Arsdale said.

The buzz around Kamen's invention began in January, when the online version of Inside magazine reported that Kamen was part of a $250,000 deal for a book that would tell the story of a top-secret invention. The proposal for the book included testimony from a number of prominent technologists who had seen the invention, including one who said it could be bigger than the Internet.

On the Web, and in the media, a frenzy ensued. Pictures of a scooter, taken from a patent Kamen had filed, quickly circulated. But many technology watchers doubted that a scooter - even the kind of advanced, self-balancing one Kamen is thought to be working on - would have the likes of Steve Jobs oohing and aahing so loudly.

''People are transfixed by the scooter, but they are missing the bigger picture,'' said Pennenberg, who is author of ''Spooked: Espionage in Corporate America.''

Inside reports that ACROS purchased property near Kamen's Bedford, N.H., home in December and broke ground for a factory, but that the building has been stopped by local opposition.

Few people know what Kamen has accomplished, or how close he might be to the breakthrough he plans to turn into a book. But the clues uncovered by Pennenberg would seem to indicate that the goal of the secretive Ginger project is both more important, and less sexy, than it first seemed. Kamen could not be reached for comment yesterday.

''I'm sorry it's not a levitating scooter or `Beam me up, Scotty,''' said Van Arsdale, who is quoted in the Inside article. But ''what really might change the world here is distributed power generation.''