News, Is Walmart's WAVE Concept Truck The Fuel-Efficient Future Of Semis? (gas, biodiesel)
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In the article is says Wal-Mart built it - but also says Wal-Mart has no plans to put them into use.
I read it a little differently... here are the pertinent quotes, with my emphasis added:
Quote:
"That's why Walmart is getting into the truck-design business with the WAVE--Walmart Advanced Vehicle Experience--concept."
"The retail giant did not reveal any plans to produce the WAVE, and in fact it would be highly unlikely to get into the truck business."
In other words, they are said to have participated in the design. That might reasonably consist of giving Peterbilt their input on what would make a truck better for their purposes, then reviewing what Peterbilt came up with.
Then some PR guy came up with the idea of slapping some Wal Mart logos on the prototype so it looked more like real-life in the photos. Wal Mart paid a fee, and got bragging rights, while Peterbilt got broader exposure to their project, and to their concept vehicle.
I'm guessing that's how it really happened, and if Peterbilt does happen to build a better truck, Wal Mart will probably buy some.
It isn't done through the terminals, but through a computerized power management system. Hybrid vehicles use them, solar PV systems use them. At times the generator might be generating more power than the motor is drawing so the battery can be charging, while at other times the motor might be drawing more power than the generator is putting out, so the battery can be discharging. In addition the regenerative braking systems generate additional electricity, but intermittently. The power management system handles the complicated balancing act required to have it all work out OK.
Any power management system that didn't direct power where it was needed and could be best used would be poorly designed. I can't imagine any engineer or computer scientist would commit such folly.
Regardless of the system managed, load will always be drawn at the battery terminal, if power is supplied to that terminal from another source (photo voltaic, generator or other) resistance will determine the path taken by the electrical power delivered. Assuming power is generated at a turbine, and delivered to a battery terminal, while the vehicle is drawing from that terminal (aka moving), power will be moved from the terminal to the engine without going through a battery. This in part due to the nature of battery design, basic physics, and inefficiency of storing rather than permitting a direct path to needed power. All batteries have a limited life, it is folly to try and waste that life.
Likely during operation, when hauling any load, the generator is driving the electric engine and keeping the battery topped off. There is no need, or good function, to imposing a battery in this instance. When in a parking lot, standing, or at idle, turning off the turbine and powering the vehicle through the battery make sense.
Note, we have no information on the power of the electric engine, the battery size (in KWh), or really much else. This is unfortunate as we are forced to conjecture.
I read it a little differently... here are the pertinent quotes, with my emphasis added:
In other words, they are said to have participated in the design. That might reasonably consist of giving Peterbilt their input on what would make a truck better for their purposes, then reviewing what Peterbilt came up with.
Then some PR guy came up with the idea of slapping some Wal Mart logos on the prototype so it looked more like real-life in the photos. Wal Mart paid a fee, and got bragging rights, while Peterbilt got broader exposure to their project, and to their concept vehicle.
I'm guessing that's how it really happened, and if Peterbilt does happen to build a better truck, Wal Mart will probably buy some.
There's one more system in the flow, which is typical for "hybrids"... The turbine drives a generator which charges batteries, and power from the batteries drives the electric motors(s).
Only if that is how the system works. Large earth movers frequently use direct systems without batteries in between as introducing batteries also introduces lots of problems for larger vehicles.
Since one of the goals is weight savings, batteries only add to a problem they are trying to mitigate. In this system, there really is no need to use batteries as an added part of the flow. Cars are a different story because they aren't all that weight conscious, just a few hundred pounds makes a lot of difference when transporting goods and many fees are charged by weight.
I read it a little differently... here are the pertinent quotes, with my emphasis added:
In other words, they are said to have participated in the design. That might reasonably consist of giving Peterbilt their input on what would make a truck better for their purposes, then reviewing what Peterbilt came up with.
Then some PR guy came up with the idea of slapping some Wal Mart logos on the prototype so it looked more like real-life in the photos. Wal Mart paid a fee, and got bragging rights, while Peterbilt got broader exposure to their project, and to their concept vehicle.
I'm guessing that's how it really happened, and if Peterbilt does happen to build a better truck, Wal Mart will probably buy some.
At least that's how it occurs for me.
We shall see. It isn't that I don't want to see these in use all over - just seemed more PR than anything else at the moment. And that statement doesn't give me hope that this is really going anywhere. I could be wrong and hope I am...
I wonder what it costs extra to build, if these were to be peterbuilt's main OTR Truck. I ams ure the one off was $1m+
Since big OTR trucks cost a lot anyways, adding $50k-$100k to the price - assuming that is all it is as I have no idea, but getting double the mileage may make sense for a lot of bigger companies. Now if its $500k more - I don't see a ROI.
Here's my math - rounding and assume an average $4/gal for diesel, since that is what I pay at the moment.
100k miles a year / 6 mpg = 16,666.66 gals of fuel X $4/gal = $66,666.66 in fuel for the year. Half that and you saved $33k... I know people that deliver cars in F450/550s that easily do 100k miles a year, so I can only assume that the big cross country OTR companies do AT LEAST 100k miles per year.
We shall see. It isn't that I don't want to see these in use all over - just seemed more PR than anything else at the moment. And that statement doesn't give me hope that this is really going anywhere. I could be wrong and hope I am...
I wonder what it costs extra to build, if these were to be peterbuilt's main OTR Truck. I ams ure the one off was $1m+
Since big OTR trucks cost a lot anyways, adding $50k-$100k to the price - assuming that is all it is as I have no idea, but getting double the mileage may make sense for a lot of bigger companies. Now if its $500k more - I don't see a ROI.
Here's my math - rounding and assume an average $4/gal for diesel, since that is what I pay at the moment.
100k miles a year / 6 mpg = 16,666.66 gals of fuel X $4/gal = $66,666.66 in fuel for the year. Half that and you saved $33k... I know people that deliver cars in F450/550s that easily do 100k miles a year, so I can only assume that the big cross country OTR companies do AT LEAST 100k miles per year.
The operation of a vehicle is only part of it's carbon footprint story. It costs a lot of carbon to make, maintain and retire a vehicle. Viewing only carbon produced by fuel consumption may miss half the story.
Heavy-duty trucks spend more time on the road than passenger vehicles, so improving their efficiency can have a major effect on emissions--and their owners' bottom lines.
That's why Walmart is getting into the truck-design business with the WAVE--Walmart Advanced Vehicle Experience--concept.
Might change the direction of the trucking industry.
Consolidated Freightways changed it when they developed Freightliner - still in production today. The industry used to be dominated by Reo, JMC, White, and others:
I just passed a Jimmy and a White,
I been a passin everything in sight,
Six Days on the road and I'm a-gonna make it home tonight..
Dave Dudley
It isn't done through the terminals, but through a computerized power management system. Hybrid vehicles use them, solar PV systems use them. At times the generator might be generating more power than the motor is drawing so the battery can be charging, while at other times the motor might be drawing more power than the generator is putting out, so the battery can be discharging. In addition the regenerative braking systems generate additional electricity, but intermittently. The power management system handles the complicated balancing act required to have it all work out OK.
That is a misunderstanding of what a generator is, a battery is and their relationships.
The Chevy Volt is a good example of a smaller scale of what the topic concerns. The Volt is always electric motor driven, all power to move the vehicle comes from the battery, there is no transmission to discriminate from electric or the gasoline engine, the gasoline engine simply provides the necessary current through the battery but can isolate the battery from providing current to the motor.
PV systems with batteries don't manage things as you stated. The array provides current to the battery via a charge controller. The purpose of the charge controller is not to manage from where a load obtains current, the charge controller manages the harvest (sources) to the battery. You can have excess current flow to another system when the primary battery reaches a predetermined state of charge but that is then a separate system and is not connected to the primary battery. The reason for this is that the load on the battery might not be compatible with the current the array provides such as is the case where the battery provides the power for AC systems via an inverter. This is a very common scenario in almost every PC system that has batteries.
PV panels are not generators, they function like batteries in that they do not supply anything nor convert harvest to heat or other form of energy as would a generator when no load exists. A generator always provides electricity and if there is no load, that electricity is shunted or converted into another form of energy.
In the case of the vehicle in the topic, this is something that can weigh in excess of 80,000 pounds, it can't carry enough battery capacity to move it more than a very limited distance unless the batteries act as a conduit for current flow. In that case the batteries aren't needed, there are far more efficient ways to get the electricity from the generator to the motors.
We shall see. It isn't that I don't want to see these in use all over - just seemed more PR than anything else at the moment. And that statement doesn't give me hope that this is really going anywhere. I could be wrong and hope I am...
I wonder what it costs extra to build, if these were to be peterbuilt's main OTR Truck. I ams ure the one off was $1m+
Since big OTR trucks cost a lot anyways, adding $50k-$100k to the price - assuming that is all it is as I have no idea, but getting double the mileage may make sense for a lot of bigger companies. Now if its $500k more - I don't see a ROI.
Here's my math - rounding and assume an average $4/gal for diesel, since that is what I pay at the moment.
100k miles a year / 6 mpg = 16,666.66 gals of fuel X $4/gal = $66,666.66 in fuel for the year. Half that and you saved $33k... I know people that deliver cars in F450/550s that easily do 100k miles a year, so I can only assume that the big cross country OTR companies do AT LEAST 100k miles per year.
Indeed.
Not to mention that if a vehicle is being used to haul inventory, introducing a battery powered system being fed through a generator removes carrying capacity from the hauler, no small matter. In OTR vehicles, weight is very high on the priority list and if it comes to batteries or materials, unless it is hauling foam, every pound counts.
For this reason, generator to motor direct is what is likely being investigated, not some hybrid system that functions like most hybrid cars. Once on the road, the batteries reduce carrying capacity that can't be managed. You can load a trailer to account for a reduced fuel load and add fuel as material is removed but batteries are always carried. If the materials being carried have significant value, the weight of the batteries could represent tens of thousands of dollars or more in lost revenue per trip.
I agree with you Mack Knife on the above. I wasn't referring one way or the other to whether the truck had a battery bank or not. Only that 13 mpg saves a lot of coin vs. 6 mpg when you drive 100k miles a year. I thought the purpose of the new truck was that it was a lot lighter? So MORE freight could be loaded, as well as, get double the mileage. Unless I missed something? I believe that was your point as well. I do get your point on an early replacement cycle and also that making the truck has an environmental cost. I don't know how that cost compares to making a traditional truck though.
Batteries providing the sole power to an electric motor is not a good way to move weight and especially weight at highway speeds. My Volt demonstrates that to me all the time. It is a great economical city car and it is only an OK highway car as far as efficiency is concerned. If we were always driving longer than 60 miles a day and on the highway, a diesel Cruze or VW would be more efficient than the volt. I am also not allowed to pull ANYTHING with the volt, because the electric motors can't take it.
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