We've said it time and again: waste is a sign of inefficiency, especially when it's wasted energy. The principle behind the regeneration of hybrid vehicles is that waste energy -- from brakes, from downhill momentum, from the engine running when not moving -- should either be used or eliminated. But as good as they are at capturing this wasted energy, hybrid-electrics aren't perfect. There's still a lot of energy going to waste as heat. But BMW may be able to do something about that.
BMW research has revealed its new "Turbosteamer" project, using the waste heat in the engine exhaust to drive a secondary steam engine, boosting vehicle performance by 14hp and reducing fuel consumption by 15%. You can find technical details in the usual locations: Autoblog has an English-language copy of the BMW press release, while Gizmag and Green Car Congress go over the specifics.
This is still in the labs at BMW central, so there's no real word on how expensive the system is or how soon it could be in production vehicles (the press release says "within ten years"). Still, it's notable that the mechanism doesn't involve a total refit of a vehicle, so it could (in principle, at least) be added with little difficulty to existing car designs. More importantly, since traditional hybrid-electrics don't capture the exhaust heat, this could easily be a way to boost both the efficiency and the power of hybrids. I'm not certain how much exhaust heat comes from hydrogen fuel cell vehicles, so the applicability there is unknown; of course, battery-only cars don't generate engine heat, so this system isn't likely to have much use in those models.
The bigger picture here is that BMW reminds us that we haven't come anywhere close to maximizing the energy efficiency of much of material environment. The next time you see heat or friction or motion simply escaping into the air, ask yourself how we could eliminate that waste. In some cases, it will be by preventing the waste from being generated in the first place; in others, as with the Turbosteamer design, it will be by turning that waste into a resource.
The entry at GCC is temporarily unavailable due to Typepad problems, but I'll repeat what I said there:
The 15% fuel economy improvement claimed by BMW isn't going to get the attention of the sort of people who spend money for the BMW label. Further, such an improvement in a car isn't all that attractive; such hardware would be used much more intensively and pay off faster paired with heavy diesel engines, such as over-the-road trucks and ocean vessels.
E-P, I think you've forgotten that BMW is more than a high-end label manufacturer, at least outside the US. BMW makes plenty of workhorse vehicles, including over-the-road trucks, for use in Europe. The people who spend money on those kinds of BMWs would see some value in this technology.
Whether BMW includes it in its passenger vehicle fleet depends in part on whether the signal elements of high-end demand start to include efficiency.
The news item at GCC says it's aimed at the 3-series.
The thing that might sell this is the extra 20 Nm of torque rather than the slight increase in economy. Getting more out of less is always good.
Shortly after reading the above entry, I came across the following BBC story:
This article describes a ramp embedded in the roadway, which is hooked to a generator to produce electricity when cars pass over and compress it. The intended application is to power stoplights and traffic signs.
Now, it seems that this would only qualify as a waste-harnessing application if the device was installed in a location where vehicles would otherwise be braking anyway--perhaps at the bottom of a hill, or at a mandatory "stop" sign. But it still seems like a neat idea, and a serendipitous example of the sort of thinking about waste energy proposed in the entry above.
Bmw is more about engineering then anything else and as such this falls right into line with what they do best.