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Paul McCready on BEVs versus FCVs; plug in hybrid mention too.

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  • Felix Kramer
    http://www.greencar.com/index.cfm?content=dialogue3 Green Car Journal Online Dialogue On efficiencies, energy, and why we need electric cars Paul MacCready
    Message 1 of 1 , Aug 2, 2005

      Green Car Journal Online

      Dialogue > On efficiencies, energy, and why we need electric cars

      Paul MacCready Speaks Out
      ...on efficiencies, energy, and why we need electric cars
      Interview by Ron Cogan

      Dr. Paul MacCready is no stranger to advanced technology vehicles. His
      company, Southern California-based AeroVironment, was responsible for
      building the famed GM Impact electric concept car that was unveiled at the
      1990 L.A. Auto Show, as well as the GM Sunraycer solar car that preceded
      it, an ultra-efficient machine that won the Australian Sunraycer in 1987.
      His lifelong focus on efficiencies and the technologies that achieve them
      have won him many honors, from the Lindbergh Award, Guggenheim Medal, and
      Howard Hughes Memorial Award to NASA’s Public Service Grand Achievement
      Award and the Chrysler Award for Innovation in Design. His innovative
      Gossamer Condor won the award for the first sustained, controlled
      human-powered flight; the Condor now hangs in the Smithsonian Institution
      alongside Lindbergh’s Spirit of St. Louis and the Wright Brothers’ 1903
      Flyer. Schooled at Yale and Caltech, MacCready applies his expertise in
      physics and aeronautics to surface transportation and holds strong views on
      this subject.

      Ron Cogan: Given all we’ve learned about advanced vehicle technologies in
      recent years, is hydrogen our best shot at creating the ultimate low
      emission, high efficiency car?

      Dr. MacCready: “At AeroVironment, we develop land, air, and water vehicles
      using various energy sources. We have made hydrogen fuel cell systems from
      10 watts to 100 kilowatts and battery powered systems from a few watts to
      over 50 kW. We are a flexible company that selects what works best. For the
      practical role of cars, economics and efficiency strongly call for battery
      power, not hydrogen/fuel cell power. Both hydrogen and batteries are energy
      deliverers, not basic energy sources. For a car, using hydrogen to generate
      electrical energy for powering the vehicle is about one third as efficient
      as using a battery. Also, a fuel cell does not work in the reverse
      direction except in very expensive units, and so cannot serve to store
      energy from braking or give utility energy back for adjusting utility
      levels. Every house, along with electricity, becomes an energy source for
      the battery-powered car.”

      RC: You’re noted for embracing efficiencies. Could you explain?

      Dr. MacCready: “We should learn to get by on much less energy and get
      energy from the permanently available resources of solar radiation, wind,
      streams, waves and tides, and carefully grown crops. We can do much of
      this. We can make homes and factories that are very power efficient, and we
      can make cars that are very power efficient. For example, we have made a
      ceiling fan that uses only one sixth the electrical energy of a typical
      ceiling fan – a two time improvement in blade efficiency and a three time
      improvement in the old fashioned electric motor.

      “For cars, the choices are energy sources and travel efficiency. It is
      useful to start from ultimate efficiency – say a car with no drag and with
      100 percent efficient propulsion. This is a nice way to start designing
      cars instead of taking last year’s model and having to improve it. Such a
      vehicle will have infinite range if we ignore the power steering, lights,
      horn, etc. Backing off from the perfect efficiency picture, we can have
      power coming from a lithium battery with 93 percent in-out efficiency, low
      drag tires of 0.7 percent of the weight they support, low aerodynamic
      drag…say the CD equals the 0.18 that was achieved with the GM EV-1, and
      realize that drag reduction devices can probably cut this down by over a
      third. The car should have a 300 mile range at good speeds and acceleration.

      “This range has already been achieved by AC Propulsion’s two-person vehicle
      using 6800 small lithium cells of the type used for cell phones and
      microcomputers – at present expensive, but clearly illustrating the point.
      For car efficiency, the use of batteries which are charged from the utility
      grid is rather appealing. The batteries also get a charge from regenerative
      braking during stops and when descending big hills. With a two-way charging
      connection to the charging grid, the car can help the utility company
      continually balance the short-term variations of the grid’s needs plus the
      long term demand for running home air conditioners on hot days. The energy
      so used is recovered late at night, say midnight until 6 a.m., by normal

      RC: So you’re saying that from the standpoint of efficiencies, we should be
      looking to battery electric cars?

      Dr. MacCready: “This battery-powered car is a great goal for the future,
      but is a bit expensive now because of the cost of the batteries.
      Incidentally, the lithium cells used would offer about 200 watt-hours per
      kilogram (Whr/kg), compared to 35 Whr/kg of lead-acid cells or about 60
      Whr/kg for nickel-metal-hydride cells. Lithium cells of over 50 percent
      greater energy/kg can be expected in a few years. We do continuing
      investigation of lithium cells for our small drone airplanes as well as
      keep up with larger cells prepared for cars. Lithium cells, incidentally,
      have very high power outputs as well as energy outputs.”

      RC: And fuel cell vehicles?

      Dr. MacCready: “Fuel cells do not deliver enough energy to be really useful
      for cars. A vast new charging system would have to be created to supply
      hydrogen fuel cell vehicles. Considering all the benefits and disadvantages
      of hydrogen/fuel cell systems for standard cars, the potentials seem too
      few. Efficiency is down, it only goes one direction, carrying capacity
      (range) is low, complexity is high, and very expensive… and H2 leakage
      represents a serious problem. The government’s virtual exclusive attention
      and support for hydrogen fuel cell cars, not battery-powered ones, is
      decidedly strange.”

      RC: Then what should the government do specifically to help lead us in what
      you would consider the right direction?

      Dr. MacCready: “They should be supporting finding a non-polluting source of
      energy for movement and mobility. It should be whatever can be made
      available that will be relatively inexpensive, and battery power fits this.
      I think that ethanol properly made from the right crops can be a fuel that
      is efficient, where it balances the CO2 of the atmosphere that it collects
      and releases. But the ethanol made from corn doesn’t balance… you end up
      with bad CO2 coming from this. It is a type of fuel that’s like fossil
      fuel, which can’t balance the CO2 problem. It deserves more attention and
      there are other fuel sources associated with it, but not all problems have
      been resolved and you’d have to grow an awful lot of appropriate plants to
      make this technology one that works. But it is moving along.”

      RC: Should we be looking at lighter or more exotic materials to increase
      vehicle efficiency?

      Dr. MacCready: “There are groups working on plastic and steel. But it turns
      out that by processing it properly, you can make steel much stronger than
      that which is used in ordinary cars, and it doesn’t cost much to do that.
      So, you could make a car that is carefully designed with this new
      technique, that weighs maybe two-thirds what a regular car weighs, and that
      weight can save you fuel that you’re consuming by cutting down on the
      amount of energy needed to move.”

      RC: Do you feel that people really care about vehicle efficiencies?

      Dr. MacCready: “People buy cars for image and faster acceleration. The
      weight of the car doesn’t matter to them. Heavier is better. But we will
      have to pay attention to this as time goes on because, if you’re paying $5
      a gallon for gasoline, you care about efficiency. If you’re paying $1 a
      gallon for gasoline you don’t care about efficiency. There will still be
      people who don’t care about efficiency even at $5 dollars a gallon. A
      couple of articles I’ve read say that the gasoline we’re burning now has
      real costs of about $5 a gallon if you attribute other things, such as some
      percentage of our exercise in Iraq, to the price. If you put all the
      numbers in it we’re burning about $5 a gallon gasoline, but it’s being paid
      in other ways. We don’t appreciate the subsidies that are going on.”

      RC: If you had your way, what kinds of cars would we be driving in the
      short years ahead?

      Dr. MacCready: “The cars that this field should have for the next five to
      15 years should be hybrids with enough electricity built in to provide all
      your transportation for maybe a 60-100 mile range. The average driver of
      such a car would operate exclusively on the battery for 80-90 percent of
      the time, with the few trips farther out requiring use of the gasoline
      motor to go any distance they want. As the cost of batteries goes down in a
      couple of years, the price for 80 miles will be low enough so this is a
      very logical direction. If you use gasoline as the other element to go long
      distances and you find in five to seven years that the price of batteries
      keeps going down, you’ll be able to get 300 miles from your battery and you
      won’t need the other gasoline power source in your car. It won’t matter
      whether you get that one or the model that goes just 80-100 miles on
      battery power, with gasoline used for long distances. If the gasoline costs
      $5 a gallon by then…it won’t matter because you won’t use very much of it.”

      -- -- -- -- -- -- -- -- -- -- -- --
      Felix Kramer fkramer@...
      Founder California Cars Initiative
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