How can you patent a perpetual motion machine?

Allegedly, by patenting different parts of it – because patent offices do not accept claims for perpetual motion machines. Of course, nobody has ever built one, otherwise we’d all be riding around in electric cars powered by infinite supplies of electricity.
The UK Patent Office notes that you cannot get a patent on “articles or processes alleged to operate in a manner clearly contrary to well-established physical laws” as they are “regarded as not having industrial application”. Any machine that generates more energy than it consumes is either a nuclear reactor or breaches the second law of thermodynamics.
But the Irish company Steorn, which has brought attention to itself by claiming to have a magnet-driven machine that will generate more energy than is put into it (and has taken out an expensive advert in The Economist rather than publishing a scientific paper or even building a few prototypes) says it will get around the restriction on patenting its invention by splitting it into components and patenting those. Then, by assembling them, it will have a patented energy generator.
Guardian Unlimited Technology | Technology | Newly asked questions: How can you patent a perpetual motion machine?