Re: resistance to carfree
- Christopher Miller <christophermiller@...> wrote:
"comments are inevitably met with rejoinders like "cars aren't going
anywhere - get used to it","
[KS] That's a common argument for lots of things, that it's inevitable. But if it's inevitable then it doesn't need to be so vigorously defended :) Nobody vigorously defends a brick's fall to the ground if you let go of it, it just happens and anyone who doubts it is ignored, not attacked.
[CM] "The assumption seems to be that we will all plug in our spanking new e-mobile at night"
[KS] Many regions already have different rates for "peak" (during the day) and "off-peak" (basically, midnight to 6am) electricity use. And the idea of "smart meters" - electricity meters sitting inside your house so you can see immediately how much you're using and what it costs - is slowly spreading. So in principle you could encourage people to only recharge at night just with the lower price and the information right in their face about it.
Of course if you had the same off/peak rate and only dumb meters then you'd get that problem, yes. But this just shows that anything by itself works badly, you need a combination of measures to make it work well.
Incidentally, you could do it with regular power leads, nothing special required. A typical battery capacity for these cars is 8kWh, to recharge that in 8 hours draws as much current as your toaster. So you'd need a bit of insulation on your power cord to stop it getting too hot, but apart from that, easily done.
[CM] "But at the same time, a full battery apparently only gives you about 100 miles (i.e. 160 km) of driving, which certainly put a crimp on long-distance driving unless an infrastructure is put in place"
[KS] While this is a problem in marketing terms, it's not really a practical problem, because less than 1% of trips taken in cars are over 100km. For that small number you could take the train or rent a petrol-driven car.
[CM] "I have yet to see anyone really explore all the implications of what battery-powered electric cars would mean for electric consumption and compare that with what can safely be sustained."
I have. It's a fairly simple calculation. Overall we wouldn't have to build any more power plants - most operate at far under capacity most of the time, and well under at night when most of the recharging would take place (ideally).
But their total output would have to increase. The average vehicle across the West travels about 14-15,000km annually. So the 160km range would take about 100 recharges (a bit more than just 14,500/160, since you won't drain the battery to zero). The 8kWh 100 times would thus be 800kWh annually.
The average household in Australia or the US has a bit under two vehicles. So the drain would be 1,600kWh per household. Electricity consumption varies a bit between countries, but in Australia it's about 6,400kWh. So we're looking at a 25% increase in domestic power consumption.
Looking at it nationally, Australian in 2008 produced some 244 billion kWh of electricity. We had 14.4 million vehicles. If all of them followed the scenario above, we'd be looking at,
14.4 million x 800kWh = 11.5 billion kWh
more electricity required. Given that our consumption of electricity already goes up by 2-4% annually - 5-10 billion kWh - this would be quite manageable for the grid as a whole. Not really an issue.
In Australia it wouldn't help our greenhouse gas emissions at all, because the bulk of our electricity is generated from coal. An average car using petrol and an electric car whose electricity is got from coal generate roughly the same emissions.
[CM] "What are the power requirements for private electric automobiles to carry a given proportion of the population compared to those of a fleet of electrically powered public transit vehicles to carry the same proportion?"
Obviously the mass tranist requires much less energy. You can see this just from the typical ridership and weights of different vehicles in Australia,
Car, 1.5 people / 1 tonne = 1.5/t
Bus/tram, 25 people / 7.5t = 3.3/t
Train, 125 people / 30t = 4.2/t
Let alone the rates of a popular and well-run public transport system, which have about twice as many people as the figures above.
In terms of energy use, the other issue is that if you want your energy source to be renewable, to make cars all run on it you need to change the power station and the cars; to make trains and trams run on it you only need to change the power station, since they're already electric. There are also far fewer trains/trams than cars, again because of how many people each typically carries. So it's cheaper and quicker to change trains/trams than cars.
But as has been emphasised on this list and in the newsletters so often, whatever cars are powered with, cities with few or no cars are just more pleasant and safe to live in.
- No surprise here, and this is something I've noticed. In the USA, every time a new LEED-certified "green" building is built on the outer edge of the city limits, the mayor/city commission go into spasms at some ribbon-cutting ceremony to introduce the city's "commitment" to the environment. The owner of the building typically gets a wad of taxpayer money and free publicity on page 1A of the local newspaper.
Of course, the mayor and city commission conveniently forgot to mention that the building was located where it is because no other land is available--thanks to the fact that it's probably illegal to subdivide large, low-density lots. Also, since the building owner was required by law to provide more parking spaces than they'll ever actually need, it was forced to a large, remote lot, since nobody wants to pay for the parking garage that would be required elsewhere.
> "This was a huge surprise," says Environmental Building News (EBN)
> executive editor Alex Wilson, author of the article. "I knew that
> transportation energy requirements were significant, but I was amazed
> at the differences." For the article, Wilson collected average U.S.
> data for commute distance, vehicle fuel economy, the split among
> different commuting options, and the number of square feet of building
> per office worker to normalize transportation energy intensity in Btu/
> square foot per year. He was then able to compare that transportation
> energy intensity to the average building energy use (also in Btu/ft2-
> yr) for average existing office buildings and energy code-compliant
> buildings (see table below).