Tuesday, October 6, 2009

Fuelish Pleasures

Would you like to know the simple, stupid solutions to saving incredible amounts of gasoline, about 40% actually, with very little expenditure of public or private money?

Look at the sticker on a recent model car or SUV. It is likely to say something like “Highway mileage 25, city mileage 18.” So, if you want to save 37% of your gas bill on that vehicle, all you have to do is avoid city driving. It’s a no-brainer.

But wait, you say. Don’t be an idiot, I have to commute to work every day or I would be driving a bicycle/motorcycle/donkey cart. That commute is always in traffic, every other idiot (author excepted) is on the same road in front of me. My average speed is maybe 20 miles per hour and I’m lucky to get 18 miles per precious gallon.

Census and government statistics agree with you. In 2007 there were 136 million cars on the road, averaging 22.5 MPG, traveling an average of 12,300 miles per year, 75% of which was commuting to work, getting groceries, picking up the kids at the soccer game, etc. The only time you get to drive on a highway, on average, is either on vacation or in rush hour traffic. Probably 15% of those 12,300 miles are on a nice, uncrowded highway where you can cruise at the highway mileage so generously listed on the vehicle sticker. It hardly matters what mileage your car advertises. It gets zero miles per gallon stopped in a line waiting to get through a congested intersection. Right?

In a poll by a WSJ reporter, certain Congress people and NYC officials admitted it was national and local policy NOT TO PROVIDE ROAD IMPROVEMENTS! Why? To discourage people from buying cars, adding to urban congestion, noise, pollution and foreign dependency on oil. That’s one big reason the potholes don’t get fixed, the money gets spent on traffic tickets and surveillance cameras instead, why parking meters always work and parking garages never get built, why states insist on converting highways built with public money over to toll roads. The politicians, I’m sure, all drive SUV’s. They plainly don’t give a damn about the hours you spend stuck in a linear parking lot trying to get to work to pay their salaries. It makes me angry.

There is a lot they could do. There is a lot we could do.

We could probably gain 264 hours per year, on average, by not having to commute at all. That’s more than a month’s working time plus overtime. Think you could use the extra income, or that your company could use the extra labor? You bet. 3.6% of people worked from home in 2005. That’s probably doubled by now. Many firms are allowing employees to work at least a few days a week at home. An enlightened government could provide tax incentives for this. But that costs state and local fuel taxes for the gas you save.

Some jobs can’t be done at home. You can’t fix machinery, ship cartons, or drive trucks from home. On the other hand, few jobs actually require people to work on a schedule that requires peak hour commuting. Forget staggered shifts - how about letting people commute on their own convenient schedules? I bet 25% of commuting traffic can be taken off rush hour with those simple changes. That would make an enormous difference in congestion.

Even where public transportation is available, which is only in about 10 US cities, people vastly prefer their own cars. They have good reasons.

But these are not new ideas. We have been talking about them for decades and nothing much changes. Let’s look at what newer technology can do with vehicle transportation.

Last year in this Blog I described a better transport system (“The System is the Solution”). Let’s take a closer look.

Futuristic designers in the Venus Project have drawn up transport modules called “pods” that fit into high-speed magnetically levitated trains. The trains travel at supersonic speeds between cities and then the pods debark to their independent destinations. It’s a great idea. We already have the pods, we call them automobiles. We lack the maglev trains. Here is a pretty good alternative we have been looking at since 1969, one that was actually implemented (and then killed) in California (the PATH Intelligent Highway).

A vehicle at speed uses energy mainly two ways. Most of the energy use is aerodynamic. That energy goes up roughly in proportion to the square of the speed. The second factor is hysteresis loss in the tires, which flex and heat up. That loss is roughly proportional to the weight of the vehicle. Both can be cut down radically with existing technology.

The number of cars that can co-exist on a road depends on their spacing. At 264 feet, the recommended spacing for cars at 60 MPH, a mile of 2-lane road holds only 37 cars. The throughput of this road at 60 MPH is 2,220 cars per hour.

With an intelligent highway system, cars can be packed in squads of 25 vehicles per squad, each only 3 feet apart. In effect, the cars are drafting on each other’s tail wind, which immediately saves 75% of the aerodynamic energy. Under computer control, this squad can safely travel at 100 MPH. The mile of 2-lane now holds 556 cars. The throughput is up to an astounding 55,600 cars per hour. That is 25 times what the same road could do before. There is no possible solution to highway congestion other than intelligent roads of this sort. There is simply not enough real estate to build new roads to this capacity. Either we move toward this solution or we give up cars.

In a conventional balloon tire, the flexing of the side wall creates heat which causes the air inside the tire to increase in pressure. Heat is lost through the tread, the side wall and the rim. At higher speeds, tire life is short and a blowout can be a disaster. I’m sure I would be insecure moving 100 MPH only 1 meter from cars in front and in back, knowing that the failure of any tire in squad would be a train wreck. Fortunately, we don’t need balloon tires.

The Mars rover had an interesting spiral hub (see illustration) that saved a lot of weight and failure modes over balloon tires. The spiral hub is actually a spring. The tread flexes evenly around the hub and the springs absorb shock like a balloon tire. The only rubber is the tread.

Michelin invented a similar design about ten years ago called the Twheel (see illustration). Again, there is a springy interior web in place of an air sac. The only rubber is on the rim, which can be replaced by itself. The beauty of this design is that it can’t go flat, and that it rolls along with far less energy use than a balloon tire. Hysteresis losses are minimal. A car drafting in a squad at 100 mph with Twheels uses about 20 horsepower. That means it can travel over 100 miles on a gallon of gas, without resorting to hybrids. Think what you could do with electric vehicles like the Tesla. How hard could it possibly be to also charge the battery while you drive, using DC power lines embedded in the road surface?

The critical piece of technology for an electric car is the battery. GM found a really good battery when they were exploring the EV-1. That battery was a form of NI-Mh storage battery made by Ovonics. They did not use it until they found that the failure rate in the lead-acid batteries was killing them. Then they bought a controllng interest in Ovonics and put out a few thousand EV cars with this excellent battery. The cars were never sold, only leased. At some point they sent out notices, US Marshals and trucks and picked up every last EV, often over the adamant objections of their drivers. Then they sold their interest in Ovonics to ... Chevron. You can’t buy an Ovonics battery for development today. Chevron won’t allow it.

Please also note that the PolaPower battery technology developed by Polaroid for their instant cameras was also quickly snapped up by an investor and is no longer considered for electric cars, even though its logical development would have created a truly superior Li-Ion battery. Battery development has now gone to China.

We have to ask ourselves why intelligent roads and Twheels aren’t on the agenda of any government agency. Why was PATH killed? When the sophistication of modern cars allow them to respond to voice commands and use radar to avoid the car in front, why can’t they follow an electronic strip down a highway? Why is there a big, expensive effort for hybrid cars when the obvious easy solutions to mileage are ignored? Why is Michelin sitting on the Twheels invention? Why did GM and Chevron kill the EV electric car? Is it ignorance, dysfunction, or connivance?

1 comment:

  1. Besides Big Oil/Big Government conspiracies to keep these technologies under wraps, there is another potential reason why these technologies don't get off the ground: they are potential disruptive technologies.

    Thus, a big company wouldn't want to bother with pursuing these things, because their customers don't want them, and they can't get a big enough of a profit margin to justify pursuing these technologies.

    It's the same thing that killed the Newton, and likely doomed Xerox PARC's research to be pursued by other companies.

    The best way to get around these problems would be to found small companies to pursue things like better batteries or tires, and then let them get excited about small profits!

    Of course, yet another explanation: these technologies aren't as viable as they first appear.