It's no wonder inventors are racing to develop the best type of engine to power tomorrow's fleet of hybrids as automakers rush to get enviro-friendly cars on the road and consumers are tempted by a new $7,500 tax incentive being offered for buying one. But it's not only new inventions that are vying for a piece of the action: Microsoft co-founder Bill Gates, former Microsoft chief technology officer Nathan Myhrvold, and other entrepreneurs are attempting to put a new face on technology that's been kicking around for more than a century—an electromagnetic engine that turns mechanical into electrical energy.

The U.S. Patent and Trademark Office last week published a patent application describing an internal combustion engine that "converts mechanical energy of a piston to and from electrical energy during each piston cycle" submitted in October 2007 by Searette LLC, part of Intellectual Ventures, a Bellevue, Wash., company launched in 2000 to buy and license patents. Gates, who was still Microsoft's chief software architect at the time the patent was filed, is listed as one of 10 inventors on the application.

2010 Prius to Get 50 MPG, Solar Roof

Toyota just unveiled the third-generation Toyota Prius, a car that has absolutely revolutionized the industry and what it means to be environmentally conscious in a car-centric world.

It's easy to say that this third-generation car isn't as big of an advancement as the last two were. But I'm actually going to say that I'm pretty dang impressed.

The car is bigger, more spacious, has better acceleration and actually improves mileage number significantly. This new Prius is the most efficient production car in America OF ANY SIZE. If Honda was still making the original Insight, yes, that would beat it, but the 2010 Prius truly will be the most advanced and most efficient car on the road.

New to the car, aside from all of the various innovations that made it's tremendous mileage numbers possible, is a solar sun roof, which will keep the vehicle cool on hot days, eliminating the need for huge bursts of AC, and thus strain on the battery.

As we just noted in our rather last, rather sobering post, there isn't going to be a lot of gravy at this year's North American International Auto Show...but that doesn't mean there won't be a lot of high quality meat, especially for the greens.

In fact, I don't think I've been this excited about an auto show since I started blogging. What will we be seeing? Well, I can't say for certain, but we can start by skimming the surface of what we know already.

BYD will be showing off the world's first production plug-in vehicle, and while it won't be available in the U.S. until 2011, it's pretty impressive that China managed to beat both the U.S. and Japan to the punch on plug-in hybrids.

Fisker, will be unveiling it's production plug-in Karma. The car, which made a huge splash last year in concept form, is like a cheaper, more practical, more beautiful Telsa Roadster.

Toyota Moving Beyond the Prius: Pure EV by 2012

Toyota showed off this concept electric vehicle, the FT-EV today at the Detroit Auto Show. And while it's an adorable little micro-car concept that might never see the light of day, they used the opportunity to promise a pure electric vehicle by 2012.

Interestingly, they aren't the only ones. Ford also promised a (very similar) BEV by 2012, with the same market (urban dwellers) in mind. Toyota hinted at a 100-mile range, the same as Fords promised BEV, but it looks as if Ford will be delivering the vehicle in a more traditional casing.

The FT-EV is based on Toyota's iQ, a peppy little three-seater for young urbanites in Japan. It's Toyota's answer to the Smart Car, and the FT-EV, of course, is Toyota's answer to the electric Smart Car. Though, the Smart EV should beat Toyota to the punch by at least a year.

Toyota won't just be adding solar panels to its popular Prius gas-electric hybrid car—like the solar electric conversion kit seen at left—it'll be powering a version of it exclusively via sunshine, according to The Nikkei, Japan's business newspaper. In fact, Toyota will be relying on the solar-electric car to "turn around its struggling business," which resulted in its first operating loss in more than 70 years, the Associated Press reports.

ScientificAmerican.com and other media outlets reported last summer that Toyota was planning to begin selling a Prius with some solar panels as early as May of this year. But the latest reports are that the Japanese automaker is seeking to build a totally solar-driven vehicle.