[LINK] Mitsubishi i MiEV electric car in Canberra

[Rick Welykochy]

Jan Whitaker wrote:

> I've often wondered if there has been any study of the real change in 
> energy demands re a shift to electric from petrol in the full energy 
> chain and the effects on GH gas emisions. The power for the car 
> batteries has to come from the same power plants that are powered by 
> coal and are already struggling to meet demand, especially in summer.
> 
> Can anyone point to somewhat reliable independent analyses for Australia?

I've been wondering the same thing. One would need to compare the
efficiency of the energy obtained from both sources, through the entire
supply chain, convert both chains to standard energy units and then
compare the overall impact of various driving profiles using petrol
vs electricity.

It gets more complicated, of course, since electricity can be sourced
from dirty sources (coal) to clean (hydro, wind and solar).

I did a google of "gas vs electric cars" ("gas" instead of "petrol")
and found many discussions about this.

The first page I found says this:

<http://auto.howstuffworks.com/hybrid-car1.htm>
"A gasoline car meets these requirements but produces a relatively
  large amount of pollution and generally gets poor gas mileage. An
  electric car, however, produces almost no pollution, but it can only
  go 50 to 100 miles (80 to 161 km) between charges."

which is complete twaddle, since it ignores the costs of producing
the electricity.

This was interesting: the Mythbusters compare the two.
<http://www.popularmechanics.com/technology/transportation/4264025.html>

"Electric motors have many advantages over gasoline and diesel powered engines,
  gasoline engines are 20-25% efficient, while electric motors are 80-99%
  efficient, meaning that they convert 80-99% of the electrical energy consumed
  into mechanical energy ... Electric motors do not require the following: -
  Transmissions. - Cooling systems. - Oil changes. - Firewalls. - Gasoline/Diesel.
  - Maintenance. - Exhaust."

which is a reader comment sans references.

Here is a meatier look into the matter with heaps of references:

<http://www.slate.com/id/2179609/>
which discusses the issues raised by Jan. The article also raises the
distinctions between mid-West electricity in the USA (coal sourced)
and Pacific NW electricity (hydro).

The concluding para makes sense to me:

"Let's say the skeptics are right to some extent, though, and that EVs provide
  only marginal environmental benefits. Upgrades in power-plant technology,
  along with the creation of more alternative energy sources, would still
  make every EV cleaner. As green-car enthusiasts are so fond of saying, it's
  a lot easier to control emissions at a few power plants than at millions
  of tailpipes."

Bang on.

cheers
rickw



-- 
_________________________________
Rick Welykochy || Praxis Services

Few things are harder to put up with than the annoyance of a good example.
      --Mark Twain