I think that was a common misunderstanding/misreporting, Dean Kamen proposed using the Stirling Engine to power the Slingshot (the Slingshot being the waterpuri

I think that was a common misunderstanding/misreporting, Dean Kamen proposed using the Stirling Engine to power the Slingshot (the Slingshot being the waterpurifier which is mentioned in the linked article). At least according to How Stuff Works, they were two separate machines: http://science.howstuffworks.com/environmental/green-tech/remediation/slingshot-water-purifier2.htm http://science.howstuffworks.com/environmental/green-tech/re... "But the two devices may fit together even more harmoniously. The generator happens to make a lot of extra heat as it burns fuel -- up to 85 percent of it doesn't get used. But when the generator and purifier are connected by a tube, hot air can blow into the purifier. There, it can do work, heating the incoming water and surrounding the purifier like a jacket, trapping heat inside. With help from the generator, the purifier can be even more efficient."