As I have mentioned before, for a long-range fuel efficient vehicle, dependent on conventional fuel like the TerraLiner, it may be much more fuel efficient to use a parallel hybrid setup. The main propulsion comes from a fuel efficient large truck engine on one or both rear axles, and additional power and AWD comes from addition electric motor/generator units at the other axles. The much smaller battery can be charged indirectly through the wheels by using the motors as generators. An all-electric range of 50 km may be enough.
This setup saves a lot of space within the vehicle and gives more range with the same amount of fuel.
Hi
egn,
This seems to be MAN's conclusion as well. Although MAN has developed and implemented full serial-hybrid solutions in its "Lion City" transit buses intended for stop-start travel in urban areas, like you MAN also thinks that for long-hall driving, parallel hybrid is the way to go. See the excellent interview with Frank Redwitz that I posted in full at #1905, at
http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1959794#post1959794 . So let's just say that your view has a great deal to recommend it, and it's a view shared by an industry expert of Redwitz's stature.
When we first started discussing hybrid, I found myself sitting on the fence. I really had no opinion, one way or another, as between serial versus parallel hybrid. However, the more that I've thought about it, the more that serial hybrid seems to be the way to go,
for a motorhome application in particular. After all, the TerraLiner won't be just
any long-haul vehicle. Rather, the TerraLiner will be a motorhome, a motorhome of a specific kind: one that can drive into and out of a farmer's field, without getting stuck. The TerraLiner will be a "bad-road" motorhome, as Peter Thompson would put things.
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1. A large, 200 KW battery pack is more or less inevitable if one wants "mostly silent" camping + powerful Air-Conditioning
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Now you yourself have indicated on a number of occasions that you don't like the sound of a generator running 24/7, and this may have been one of the reasons why you opted against having Air-Conditioning for
Blue Thunder...?
But let me be very direct here: a TerrraLiner without Air-Conditioning is inconceivable. It simply will not sell, and it will be dead in the water from a market point of view. It is impossible to design the TerraLiner without Air-Conditioning. Yes, I know that you personally don't need Air-Conditioning, but you are not the TerraLiner's market. Rather, the TerraLiner's market is
AARCWPOMs:
"Active-Adventurous Retired Couples with Plenty of Money" -- see post #1983 at
http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1964731#post1964731 . Generally this means that the TerraLiner's customers will be over 65, which means that Air-Conditioning the TerraLiner becomes a health-and-safety issue. Even if elderly people are fit and active, over the age of 65 their nervous systems will still begin to degenerate. Which is why elderly people are much more susceptible to sun-stroke and heat-stroke, no matter how fit and healthy they might be. Over 65 our bodies become increasingly bad at regulating core temperature, which is why so many old people died during the heat-wave that hit Europe in the summer of 2003.
This is why Air-Conditioning will be absolutely mandatory for the TerraLiner, and not some kind of luxury option. If the TerraLiner is going to travel to places where the Heat-Index regularly rises above 100 degrees Fahrenheit, and sometime tops 120, then Air-Conditioning will be critical, given the TerraLiner's
AARCWPOMs target market.
I worked all of this out in some recent posts that you may not have read yet, because they are part of a longer posting series on TerraLiner drive-train power requirements that I am currently trying to complete. For lots of detailed arguments, evidence, graphics, and tons of links on the topic of TerraLiner Air-Conditioning, see posts #2120 to #2124, at
http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1973835#post1973835 to
http://www.expeditionportal.com/for...w-6x6-Hybrid-Drivetrain?p=1974106#post1974106 .
How much Air-Conditioning are we talking about?
Well, 60,000 BTU at a bare minimum, which is the amount of Air-Conditioning that a typical Newell motorhome carries. But probably more like 100,000 BtU, or 29 KW.
In post #2124 specifically, using various precedents, I worked out that the camper-box electrical demand of the TerraLiner when stationary and glamping in a very hot/humid climate, will probably run somewhere between
70 to 100 KW per day. Yes, this is a figure that is
vastly different from your estimate or 12 KW per day. But if you read those posts, you will see how I arrived at this figure, and you might find yourself agreeing that this figure is not unreasonable, given my arguments and the evidence that I cite.
I wish that I could find a figure somewhere on the Internet stating how many KW a Newell Coach might use per day when camping in Texas, Louisiana, Alabama, or Florida at the height of summer, when the Heat Index often runs between 110 and 120 degrees Fahrenheit for many weeks, and sometimes goes over 120. Or I wish I could find a comparable figure for a Millennium, Liberty, Featherlite, or Marathon coach. These are all premium-luxury Class-A motorhomes that typically mount 4 Air-Conditioners, totaling 60,000 BTU. But one thing I am most definitely certain about is this: a large, 45-foot Class-A motorhome camped in Louisiana in the middle of August, with 60,000 BTU Air-Conditioners running full blast to maintain an interior temperature of 75 degrees Fahrenheit, will most definitely use
much more than 20 KW per day. At a bare minimum, it will probably use at at least 40 KW per day, and I'd guess the figure is more nearly like 55 - 70 KW per day.
Yes, I know that all of this all sounds very "un-German". But as I argued in those posts, German intuitions about climate, Air-Conditoning, and what should be considered a "normal" level of residential power consumption, are radically different from the intuitions and expectations of North Americans, Australians, and Scandinavians. Germans are very "Green" tree-lovers who live in a comparatively moderate climate; they are energy-frugal eco-purists fanatically committed to alternative energy, covering their fields with solar installations and wind farms. In other words, Germans have become
very environmentally conscious and "ethical"; but that does not necessarily mean that Germans can intuitively understand what a heat index of 100 actually feels like, let alone 120....:ylsmoke:
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