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Since an iStream factory would be two-thirds smaller, it would consume about 60 percent less energy. This is either a journalist misrepresenting the actual cla

Since an iStream factory would be two-thirds smaller, it would consume about 60 percent less energy. This is either a journalist misrepresenting the actual claims, or else the actual claims have no grounding in rigorous analysis. In a nutshell-- he plas to revolutionize auto manufacturing by making the body in two steps rather than five, using composite materials instead of stamped and welded steel, but the basis of his energy estimates is the size of the building that houses the work? A little hard to take seriously.

tankenmate 14y ago
The 60 percent figure may be correct, or it may not; depending on the type of composite this might be possible, steel making, forming, and welding vs fabrics and glues. Totally agree on the wording; completely non sequitur.
brudgers 14y ago
Watts per square meter is a reasonable way to make a back of envelope calculation for the energy use of a common building typology. Given the radical realignment of energy budgets in the manufacturing process and the attention to energy efficiency in building design over the past two decades, it is not outrageous to argue that a new smaller footprint factory would be significantly more efficient. If one visits an automobile plant, one will see that a lot of energy goes into moving chassis and components from place to place. Smaller lighter pieces over shorter distances combined with fewer moves would have a significant impact on energy consumption.
ChuckMcM 14y ago
Actually you will find that Amory Lovins has done a lot of research into the costs of making cars ( http://www.rmi.org/Autos http://www.rmi.org/Autos ) which I suspect feeds into the article's analysis. There are challenges of course, when you collide with something at 70 - 80 MPH and you're in a composite material vehicle without a steel frame the energy gets distributed in harder to control ways. Its not an unsolvable problem [1] but it is another wrench in general acceptance. Another challenge is of course 'style' points but styles change so its less of an issue. I expect that the continued high cost of oil will keep these sorts of ideas popping up. I hope that some of them get to production so that we can iron out the other problems. [1] In the forgettable movie "Demolition Man" a collision system which fills the car with foam is presented. That is actually an actually proposed solution but one where false starts are hard to recover from.
- darklajid 14y ago
  70-80 MPH collision? Do you have any reliable source for working systems that protect you at that speed? I'd consider collisions at that speed lethal - or it's your lucky day. Ignoring the body material. In DE you are told (not that I can confirm that by experience) in your driving lessons that collisions > 30 KPH (K!) are very, very dangerous and that the statistical 'you might be heavily injured' line is somewhere around there. So .. I'm having trouble imagining something that hits anything else with 70-80 MPH.
  - ChuckMcM 14y ago
    McClaren (the guy in the original article) works on F1 race cars. They regularly have collisions at greater than 100MPH with out any injuries to the driver. (and yes some of them are into fixed objects like the track wall). Here in California there is a wealth of data on injury and damages in collisions between 50 and 100MPH [1]. In general, when all applicable safety systems are employed (seatbelts, nothing obstructing airbags, Etc) the injuries sustained are rarely fatal and for the most part don't required a hospital stay. We have a condition called "Tule Fog" which is a dense low hanging fog that can occur rather suddenly, which every other year or so results in the collective colliding of anywhere from 3 to 75 vehicles at speeds from 10MPH to 60MPH. Again, people don't die in these pile ups generally unless the passenger space of the vehicle is compromised (like being shoved under the trailer of a semi-truck for example). In their table of 'injuries and fatalities' for 2009 [2] out of 201,660 collsions there were 2,594 with fatalities so a 1.3% rate. [1] http://www.chp.ca.gov/switrs/ http://www.chp.ca.gov/switrs/ [2] http://www.chp.ca.gov/switrs/pdf/2009-sec3.pdf http://www.chp.ca.gov/switrs/pdf/2009-sec3.pdf
  - johngalt 14y ago
    Probably not a good day, but survivable with a modern car. Most crashes have some angle to them which reduces the forces involved. Hitting a brick wall perfectly perpendicular is rare.
rayiner 14y ago
Eh, these sorts of "rule of thumb" guesses are quite common in engineering. You fit a line to some data points and you might realize that power usage is roughly proportional to the size of the plant. In aerospace, in preliminary estimates you scale a whole bunch of random things on the gross weight of the aircraft.

tankenmate 14y ago

The 60 percent figure may be correct, or it may not; depending on the type of composite this might be possible, steel making, forming, and welding vs fabrics and glues. Totally agree on the wording; completely non sequitur.

brudgers 14y ago

Watts per square meter is a reasonable way to make a back of envelope calculation for the energy use of a common building typology. Given the radical realignment of energy budgets in the manufacturing process and the attention to energy efficiency in building design over the past two decades, it is not outrageous to argue that a new smaller footprint factory would be significantly more efficient. If one visits an automobile plant, one will see that a lot of energy goes into moving chassis and components from place to place. Smaller lighter pieces over shorter distances combined with fewer moves would have a significant impact on energy consumption.

ChuckMcM 14y ago

Actually you will find that Amory Lovins has done a lot of research into the costs of making cars ( http://www.rmi.org/Autos http://www.rmi.org/Autos ) which I suspect feeds into the article's analysis. There are challenges of course, when you collide with something at 70 - 80 MPH and you're in a composite material vehicle without a steel frame the energy gets distributed in harder to control ways. Its not an unsolvable problem [1] but it is another wrench in general acceptance. Another challenge is of course 'style' points but styles change so its less of an issue. I expect that the continued high cost of oil will keep these sorts of ideas popping up. I hope that some of them get to production so that we can iron out the other problems. [1] In the forgettable movie "Demolition Man" a collision system which fills the car with foam is presented. That is actually an actually proposed solution but one where false starts are hard to recover from.

darklajid 14y ago
70-80 MPH collision? Do you have any reliable source for working systems that protect you at that speed? I'd consider collisions at that speed lethal - or it's your lucky day. Ignoring the body material. In DE you are told (not that I can confirm that by experience) in your driving lessons that collisions > 30 KPH (K!) are very, very dangerous and that the statistical 'you might be heavily injured' line is somewhere around there. So .. I'm having trouble imagining something that hits anything else with 70-80 MPH.
- ChuckMcM 14y ago
  McClaren (the guy in the original article) works on F1 race cars. They regularly have collisions at greater than 100MPH with out any injuries to the driver. (and yes some of them are into fixed objects like the track wall). Here in California there is a wealth of data on injury and damages in collisions between 50 and 100MPH [1]. In general, when all applicable safety systems are employed (seatbelts, nothing obstructing airbags, Etc) the injuries sustained are rarely fatal and for the most part don't required a hospital stay. We have a condition called "Tule Fog" which is a dense low hanging fog that can occur rather suddenly, which every other year or so results in the collective colliding of anywhere from 3 to 75 vehicles at speeds from 10MPH to 60MPH. Again, people don't die in these pile ups generally unless the passenger space of the vehicle is compromised (like being shoved under the trailer of a semi-truck for example). In their table of 'injuries and fatalities' for 2009 [2] out of 201,660 collsions there were 2,594 with fatalities so a 1.3% rate. [1] http://www.chp.ca.gov/switrs/ http://www.chp.ca.gov/switrs/ [2] http://www.chp.ca.gov/switrs/pdf/2009-sec3.pdf http://www.chp.ca.gov/switrs/pdf/2009-sec3.pdf
- johngalt 14y ago
  Probably not a good day, but survivable with a modern car. Most crashes have some angle to them which reduces the forces involved. Hitting a brick wall perfectly perpendicular is rare.

rayiner 14y ago

Eh, these sorts of "rule of thumb" guesses are quite common in engineering. You fit a line to some data points and you might realize that power usage is roughly proportional to the size of the plant. In aerospace, in preliminary estimates you scale a whole bunch of random things on the gross weight of the aircraft.