Jed Rothwell wrote:
The cost probably is higher, because petroleum is more expensive than coal or natural gas per MJ. I meant the fuel efficiency, or carbon emission per passenger mile.
Carbon emission can be much lower - using more batteries and a genset and NO large ICE. Wind, hydro and nuclear can do this. So that argument for the large ICE falls flat on its face in the comparative picture.
At high speeds, ICE efficiency is as good as the path for fossil fuel generator => battery => vehicle propulsion.
The consummer is only interested in *cost,* and he can save half his fuel-cost with the *strong serial* design, as opposed to the present Prius with its big ICE on every occasion when he needs to go on the freeway - which for most commuters is twice per day.
The ecologist is only interested in carbon - and the ICE is a net looser there too. There is really no need for a large ICE under any possible furutre scenario, even without a major battery advance.
There is no doubt that if we had superb batteries right now, with a 300 to 600 mile range, a pure electric vehicle would be the most efficient and least polluting overall. However, since we do not, and we have to make hybrids that use some gasoline anyway, they might as well use the ICE directly at high speeds.
Illogical and incorrect. Batteries need only provide the stronger electric motor with about 60 mile range, but the larger electric motor must be freeway usable - so this is more batteries but and then a tiny Wankel genset can boost that range enormously - up to the 600 mile level on those occasions when it is required. The Prius is carrying around 500 pounds of superfluous motor/transmission/radiator. By comparison, when shifting 300 pounds of that dead weight to more batteries, and then adding a bigger serial electric motor and an 80 pound Wankel genset - wow this will do a better and cheaper overall job with no added weight gain. Hacking the Prius, even if Toyota does it, adds a lot of weight and still does not get you to freeway-ready!!
The cars have to have a heavy-duty powerful ICE no matter what.
NO WAY ! You seem to be missing the whole point.
they might as will use it at peak output from time to time to prolong battery power. High speeds and long-distance will both quickly drain the limited battery reserves of a plug-in hybrid, so you might as well resort to using the ICE early on.
NO WAY ! You seem to be missing the whole point.
Beene made the other day when he suggested that you would start the hydrogen genset the moment you left home if you intended to make a long trip.
Yes fine, but that is for the occassional long trip - a few times a year - gasoline or hydrogen or ethanol - it doesn't matter. That might end up being less efficient for that small fraction of that usage time - but we are trying to find a solution that covers 80-90% of actual mileage more efficiently. When you look at normal usage patterns, getting rid of the large ICE in favor of batteries, a freeway-viable electric motor, and a small genset wins all the logical arguments hands down.
The Wankel is only 80 pounds (maybe 120 with the larger alternator) and can provide 50 kwh. This is much less than the Prius engine - but it will allow the batteries to go the full 600 miles/day if you start the genset up at the outset of a long trip. If these long trips are only a few weeks out of a year, then why lug around 380 extra pounds for the slight amount of extra power you only need during this short period ?
The large ICE is brain-dead in an advanced hybrid when compared to the alternative!
A typical urban driver with a plug-in hybrid will use little gasoline over the course of a year even if the gasoline motor clicks on at 40 mph and above before the battery is exhausted.
Yes, but this same driver will need to get on the freeway daily, more than likely several times and does not want to piddle along on the freeway at 40 - especially when that is very unsafe. Big-rigs can easily come up behind too fast to slow down. It makes much more sense to use battery power on the freeway too - instead of gasoline, and to ditch the big enginem and add a lightweight genset. You are better off in every conceivable way.
Jones
