Andrew D. Todd
Mini-Blog #1
I do not propose to make this a public blog, and I am therefore not
going to enable comments or use blog software. It will be primarily a
place where I can conveniently respond at a length of two thousand
words to magazine articles of ten thousand words. I may possibly
use it as a place to post book reviews.
Andrew D. Todd
1249 Pineview Dr., Apt 4
Morgantown, WV 26505
adtodd@mail.wvnet.edu
Table
of Contents Homepage
Energy and Transportation
October 26, 2009
The following are a series of critiques of articles dealing with
energy and transportation. The people involved, both authors and
the businessmen they report on, have their hearts in
the right place. But good intentions are no substitute for
knowing what one is doing.
Tony Long, "Science:
Discoveries: Aug. 22, 1962: First Nuke-Powered Cargo Ship Docks"
(Aug.22.2008)
http://www.wired.com/science/discoveries/news/2008/08/dayintech_0822
This is a discussion of the nuclear cargo ship Savannah. Tony Long
concludes that the Savannah was uneconomic-- which was true-- but
proceeds to the faulty conclusion that a nuclear-powered cargo ship is
impossible. The basic problem of the Savannah was that it was
much too small to
have an efficient nuclear power installation. The one class of ships
which were in the right power range (150,000 hp-200,000 hp), the
ocean
liners, were being superseded by the airliner. At about the time the
Savannah was built, the Navy had adopted a policy of using nuclear
power in surface ships of at least 80,000 hp (aircraft carriers
and
cruisers), and in submarines, of course; oil-powered gas turbines
in
surface ships of 30,000 hp-80,000 hp (destroyers and
frigates); and
diesels in ships of 20,000 hp or less (typically fleet
auxiliaries).
The nuclear-powered merchant ship Savannah, with only 20,000 hp, was an
extremely marginal proposition, even by naval standards.
The Savannah was an artifact of economic protectionism, designed around
the assumption that cheap labor goods might not be imported, and that
the only things which it was permissible to import were things which
could not be made in America and which did not compete with American
products, eg. bananas from Central America, and certain classes of
high-end manufactures from Western Europe, such as Rolls-Royce
automobiles. A nuclear cargo ship big enough and fast enough to be
efficient would have broken the economic rules.
Now, however, merchant ships are getting bigger and faster than
they
used to be. A big and fast containership, on the order of a
Nimitz-class aircraft carrier (80,000-100,000 tons, 300,000 hp, 35
knots), operating between China and North America, might very well
employ nuclear power. Given its emphasis on speed, it would probably
dock at Prince Rupert in northern British Columbia, so as to move
cargo by rail as much as possible. The Canadian railroads running
to
Minneapolis, Chicago, Detroit, and New England could be electrified, of
course.
Daniel
Roth, "Driven: Shai Agassi's Audacious Plan to Put Electric Cars on the
Road," WIRED MAGAZINE: 16.09
http://www.wired.com/cars/futuretransport/magazine/16-09/ff_agassi?currentPage=all
See also: Chuck Squatriglia, "Better Place Unveils an Electric Car
Battery Swap Station"
http://www.wired.com/autopia/2009/05/better-place/
Roth's article is largely a profile of Shai Agassi, a software
executive who wants to build a system of electric automobiles along
lines derived from the consumer electronics industry. Agassi's primary
test market is the state of Israel, a kind of de-facto island, where it
is only possible to drive limited distances in any direction. His
alternative test market is Hawaii, or, more specifically,
the city of Honolulu on the island of Oahu. His emphasis is on using
computer systems to efficiently allocate electric automobiles
needing recharging to parking spaces fitted with rechargers, and,
more recently, to available interchangeable battery packs in
service stations. Shai Agassi is not an arrogant twit like Elon Musk
(*),
but he suffers from a tendency to force the lessons of his previous
experience into places where they are not applicable.
Daniel Roth, acting as a kind of cheerleader, does not raise the
kinds of questions which need to be raised.
Back during the 1970's oil crisis, there were a whole series of land
transportation projects funded by the United States
government. An inordinate number of these projects were
contracted out to aerospace companies with no knowledge of land
transportation. These companies were in a depressed state as a
result of the spending drawdown at the end of the
Vietnam War. There was an element of corporate welfare. More seriously,
the aerospace people tended to become enraptured with the idea of their
own technological superiority, and to proceed in deep ignorance of the
proven practices of railroading, etc.
This meant that they were always doing things the hard way, admittedly
with great technical virtuosity, but with very little in the way
of practical results.
Something similar seems to be happening now. There are a lot of
people who have been pushed out of the stagnating computer industry,
and who are inclined to use computers in all the wrong ways. In
particular, Shai Agassi seems to be attempting to force the false
analogy of the cellphone onto the electric automobile.
1. The most basic truth about automobile transportation is that
different people do not drive the same distance. A minority of people
drive much longer distances, and use up most of the energy
involved in automotive transportation. Archetypally, this means someone
with a highly skilled job who drives fifty miles to work, and fifty
miles home again, for a total of several hundred miles a week.
The nature of his skills means that he cannot just find a job down the
street. Someone who merely drives for his own convenience-- a retiree,
for example-- will drive a distance which shades over into walking
distance, say thirty miles a week. Stores, restaurants,
etc. locate themselves for the convenience of their customers, not the
other way around. The latter kind of driver does not need special
infrastructure to use an electric car. He can have a charger in his
garage, and get a week's supply of electricity in a single night.
But in any case, such a driver would only need a gallon of gasoline a
week, or possibly even as little as a gallon a month. That
is not enough to create a problem, so there is no
compelling reason for such a driver to get an electric car. What
this all means is that the electric car developer has to solve
the problems of the long-distance commuter, or he is just wasting
his time.
2. Electric automobiles are not cellphones. You cannot put an
electric automobile in your pocket and carry it on an airliner.
Worldwide standardization is meaningless. Transportation is dependent
on geography. A transportation system appropriate for Israel will
almost certainly be wrong for Montana. For what it is worth,
the world has gotten along quite well with different countries
either driving on the right side of the road, or driving on
the left side of the road. The kind of people who go
back and forth between different countries sufficiently often that
they are likely to become confused are precisely those who can
afford to hire drivers anyway.
3. Assuming an automobile has regenerative braking, it does not need
much power to travel at low speeds.
4. The time constraint means that an automobile cannot go very far at
slow speeds.
5. At least in urban areas, it is not safe to drive at high speeds on
roads which are not expressly designed for such a purpose,
such as Interstate Highways, or as the Europeans call them,
motorways.
6. As a consequence of Items 3-5, the transportation energy problem is
primarily a problem of high-speed roads, not of side streets and
parking places.
7. Experience with previous land transportation systems, such as
railroads and stagecoaches, has been that if you need to change out
your power system on a regular basis, the best thing is for both the
power system and the payload container to have their own wheels,
and to have the two connected together by a quick-release
coupling, which can be unfastened in a minute or less. In the
steam engine era, it was normal for a high-speed express train to
change locomotives every hundred miles, or about every hour-and-a-half.
For stagecoaches, the norm had been about ten miles between changes of
horses, so that a stagecoach might need a herd of a hundred horses to
keep it rolling along continuously. An electric automobile can be given
a trailer filled with batteries, with an electric connector built
into the hitch, and there can be two or three trailers for
every automobile, if that is what is required. For that matter,
one can have a trailer with a gasoline engine and gas tank, if the
situation calls for it, or a trailer mounting any other specialized
apparatus one might happen to need, such as a trolley pole. On
this basis, one does not worry about whether a power system is truly
exhausted or not, or whether it could be replenished in time to
go on-- one simply makes an exchange as an ordinary matter of
routine, and makes such credits after the fact as may be appropriate.
8. As a consequence of items 6 and 7, an electric car can have its own
internal battery, in the golf cart class, good for, say
twenty miles at twenty miles per hour, something easily within
current capabilities. The car's origin and destination are a reasonable
distance from high-speed routes, let us say, not more than five
miles (at most), and probably more like one mile, on average.
When the car gets on a high-speed route, it replenishes its internal
battery from the power systems provided for the high-speed route. One
does not need a lot of recharging stations-- instead, what one needs is
the means to attach or activate a power supply in some fashion to
large numbers of vehicles as they go up the freeway on-ramp.
There are, of course, a number of different ways to do this.
a. One can use battery-trailers and stop to change them every
half-hour or so, at something like an American truck stop; b. one
can fit the automobile with an extensible trolley (or the
equivalent) to draw power from overhead wires; or,
c. one can drive the automobile onto a transporter vehicle which
stays on the highway, and carries automobiles from one exit or
interchange to another. This system has the advantage of being
compatible with existing gasoline-powered automobiles.
There are a lot of minor variations within these three general options.
However, what is necessary is to arrive at a plan for rebuilding the
freeway, a piece of government property.
9. In terms of pure geography, Israel is something
like one of the world's ideal locations for electric
railroads. However, one gathers that railroads were
systematically neglected for the first fifty years of Israel's
existence, and Israel is only now beginning to make up for lost time.
Railroads can and do carry automobiles in transporter cars, when
that is desired.
http://en.wikipedia.org/wiki/Israel_Railways
However, for a large office building, or a shopping mall, or a
college campus, or a sports stadium, it is effectively impossible to
give everyone a good parking place. Automobiles take up too
much space, and someone or other will have to walk half a mile
to his car. On the other hand, it is possible to build a
good train station into such a building, and with intelligent
organization, the train can carry people to and from parking lots
anything up to fifty miles away, only a short drive from their
respective homes.
10. A certain type of Silicon Valley refugee knows how to sell upscale
consumer goods, but does not know how to sell public goods, and
this tends to distort his thinking. In terms of public goods,
it is not possible to do much of anything as long as the
organizer is thinking about becoming personally wealthy,
taking Bill Gates (old version) as a role-model. To
successfully build large systems involving public property, there
has to be someone more or less like Robert Moses.
http://en.wikipedia.org/wiki/Robert_Moses
Moses had inherited money, his father having retired from
business when he was nine years old, and had been educated as a
professor before going into public administration. He could get
away with doing things only because it could be taken for granted
that he was not trying to enrich himself at public
expense. Interestingly, the architect of parkways never learned to
drive-- that was something that chauffeurs did. It really does
matter that Shai Agassi sounds as if he might be a man on the
make.
(*) For Elon Musk's defenders, the word he used in reference to Randall
Stross, which I cannot quite bring myself to repeat, is indubitable
evidence of arrogant twithoot.
Jonathan Rauch, "Electro-Shock
Therapy," _The Atlantic Monthly_, August, 2008
http://www.theatlantic.com/doc/200807/general-motors
This is a portrait of the General Motors Volt project. In many
respects, it resembles Michael Shnayerson's _The Car That
Could: The Inside Story of GM's Revolutionary Electric Vehicle_ (1996)
about the EV1 project. For practical purposes, Volt seems to be a
continuation of EV1, only with somewhat different design objectives.
That is, it is apparently less of a sports car, and more of a family
car, but the design emphasis is still on achieving
low drag and the lightest possible weight exclusive of the
battery, drawing heavily on aerospace design practices to achieve
these goals.
Jonathan Rauch fails to
address the real reasons which underly General Motors' successive
failures to develop an electric car. GM's essential problem is
that
the company is organized
around gasoline, and would not have any reason to exist in
the
absence of gasoline. GM owns no roads (outside of the proving
ground),
nor does it take any responsibility for roads. On the contrary,
GM's
most lucrative product until recently, the SUV, has been based around
the tacit claim that roads do not exist.
The special genius of gasoline lies in storage. Gasoline or diesel oil
is about the most lightweight, compact, and convenient
non-nuclear
means of
storing energy there is. Electric batteries are grossly inferior
at
storing
energy. GM's successive attempts at electric car
designs have been failures precisely because they have been
attempting to force electricity into the likeness of gasoline.
The
illusion is brittle. For example, the first Toyota Prius was
unsatisfactory because it was slightly underpowered. Japanese engineers
could not quite believe how hard and fast Americans drive, and they
reduced the power accordingly. This was not a fundamental
problem,
however. It just meant that the engine had to be
souped up a bit,
and the car would get slightly worse gas mileage. It is no big
deal to
add an extra gallon or two to the gas tank. Electric cars, on the
other hand, tend to be pushing the limits of their battery
technology, and that sort of miscalculation is likely to be
serious. A
plug-in hybrid, consistently operated beyond the limits of its
battery, might well get worse gas mileage than a
standard hybrid,
because it would have to haul all those batteries around.
The genius of electricity, in distinction to that of gasoline, lies in
flow. Successful electric transportation means building an electricity
supply into the road, usually via an overhead wire. Far and
away the most effective system of electric transportation is the
electric railroad, the most perfect kind of road. There are all kinds
of different variations of electric railroads, such as subways,
streetcars, trolley-buses, and people-movers. Lastly, there
is
Personal Rapid Transit, where each train is scaled down to the size of
a single automobile to provide the maximum in flexible routing.
When
passengers want to take automobiles with them, the railroads provide
Auto-Trains, driving each automobile onto a transporter car and parking
it. Advanced transportation planners thirty and forty years ago drew up
schemes
in which PRT vehicles could be made to carry single automobiles. It was
the standard "redesign with automation" treatment-- give
everything a
computer, and design for maximum possible versatility. The problem
for
GM is
that the enlightened railroader arranges to carry an automobile by
treating it as a glorified suitcase with wheels. Any old
automobile
will do to drive onto the railroad transporter car and park
there. In
fact, a smaller automobile usually has an easier job of finding a
parking place, so the ideal vehicle for "piggybacking" on railroads
might well be something like an enclosed golf cart.
Silicon Valley companies are not especially well-managed. They make as
many mistakes as everyone else. This includes Apple
and Steve Jobs.
Silicon Valley's mistakes are bailed out by Moore's Law, by
the fact
that making an integrated circuit smaller also makes
it faster and
cheaper at the same time. When one of Steve Jobs' gadgets misses its
market, as they sometimes do, he has only to wait a year,
and then
see if there is a market at half the price, or twice the power.
Apple
does not even make any of the critical parts of a computer, such as
chips and disk drives, but uses commercially available
off-the-shelf
components. Apple really does not do much more manufacturing than home
hobbyists do. In automotive terms, Apple might be compared to one
of
those importers who, back in the 1950's, brought in various odd
European cars, operating at a level one step above used-car dealers,
yet introducing Americans to the radical idea that an automobile
did
not have to have nonfunctional tail fins. Apple makes its money by
teaching people about the exciting new things one can do with
microelectronics. The strategy of miniaturization is not applicable to
batteries, because batteries are supposed to produce power rather than
information. It is a sign of GM's moral desperation that it is looking
to Apple for guidance about how to run a manufacturing company.
---------------------------------------
Ref:
http://en.wikipedia.org/wiki/Toyota_Prius
The Tesla
The Tesla Model S is fitted with
a lithium-ion battery pack weighing somewhere in the neighborhood of a
thousand pounds, and delivering 70 Kw-H, for a claimed range of
160 miles. These figures are broadly compatible with GM's figures for
the EV1 with lead-acid batteries of about the same weight (70 miles
city, 90 miles highway). That is, the EV1's drag coefficient is about
twice as good as that of the Tesla, but the Tesla's lithium
batteries are four times better-- provided they don't burst into
flames.
It is claimed that an extended range version will be available, capable
of 300 miles. Batteries are compact, and the major
cause of automobile energy consumption at speed is aerodynamic
drag, not rolling resistance. Because the batteries are compact, they
can be stored in such a way as not to require an appreciably bigger
body. The implication is that if Tesla lengthens the frame a couple of
feet, between the driver compartment and the front and rear
wheels and sticks in another thousand pounds of batteries, that
would get them a car weighing about five thousand pounds, but
with very nearly the same power requirements as the standard
model.
The EPA highway driving cycle assumes substantial adherence to the 55
MPH speed limit. If one actually drives at 70 MPH, in a state
where this is legal, one has to expect that the gas mileage
(assuming an electric drive, as distinct from a conventional
gearbox) would
be only about 65% of that for 55 MPH. To drive long distances,
with a practical economy of time, one has to drive fast. Thus the
Tesla's actual range would be a hundred or two hundred
miles, according to model. Another point is that battery performance is
sensitive to
temperature. What is possible in California is not necessarily
possible in the Midwest, especially in the depths of winter.
The Tesla has a very high claimed horsepower (I believe about 400
hp), though this is matter of nomenclature. Unlike a gasoline engine,
or a mechanical gearbox,
the limiting factor of electric motors is generally overheating.
As Charles Kettering noted in designing the first electric
starter, one can run a motor at very high power level for a
burst, provided one does not continue. In the case of accelerating an
automobile, the greater the power, the greater the acceleration,
and the less time before the automobile reaches its designated
speed. Since this speed is restricted by law, the total amount of
energy required and consequently, the total surge of heat resulting
from acceleration is also limited.
Summing up, the performance of the Tesla is likely to be
marginal. It will depend on the user being willing to carefully plan
out his fuel supply, the way airplane pilots do. The car will not
respond well to unforeseen events which require transportation.
Barring its price, the Tesla would be a perfectly adequate car
for eighty percent of the population, but-- this eighty percent
of the population only uses twenty percent of the gasoline, and is
perfectly happy with used cars. The twenty percent of the population
which drives long distances, uses most of the gasoline, and which
is disposed to pay substantially more than $20,000 for a new
automobile, would not find the Tesla so satisfactory.
http://www.rsportscars.com/tesla/2013-tesla-model-s/