Study: Electric cars not as green as you think

Tweev,

I take it you wouldn't approve of my "100 mile burger" ride then. Back when I lived in Tennessee some of my motorcycle riding buddies and I would get together after work for a ride. We would ride some twisty mountain roads over the border into North Caroline to eat a burger at the Paddler's Pub in Hot Springs, NC and then ride home. Round trip, 100 miles. It was a great way to spend an evening!

I'm reminded of this because today I had a hankering for a burger. My wife and I eat very little red meat but every now and then I want a good burger. We drove the Prius across town to Five Guys. That was only a 36 mile trip though.

 

My Daugher took me there when we last visited her.
Be careful ... you may wish to burn you gas in another manner:

Vox Populi » Five Guys closed after visit from Inside Edition’s Rat Patrol

That's what blows me away. The article blows tons of CO2 itself ... by playing down the amount of petro profits that can be saved via EV's. It fails to address political concerns such as the use of petro profits to fund radicals ready to drop planes, nukes, bio hazards, etc, what ever they can get their hands on, on us, the end user.

 

The only hope for a sustainable future will be due to what occurs inside people's heads. Any technology is just a tool for advancement or regression depending on how it is used.

The other comment is that family size is vastly more dependent on the standard of living than any other factor. Taxation would not work since those with unconstrained families are often the poorest. Pretty hard to tax those below the poverty level. Within the US, immigration is more of a factor than the internal birth rate. If there is a way to raise the worldwide standard of living without destroying the planet in the process, then a big downturn would occur in the birthrate. It's been true throughout history once women had access to birth control. Definitely a non-intuitive lesson for me.

 

:yuck:

I see the rats have good taste.

You would have to see some of the little BBQ place I frequent to understand how little I care about rats. I would rather have a few rats and some cockroaches than to have a restaurant constantly spraying poison everywhere.

EDIT: Hopefully next time we won't have to burn so much gas. There is a new Five Guys location opening 7 miles from our house. We try to eat local as much as we can. We have a good chinese, mexican, japanese, pizza and BBQ place in our town. Unfortunately McDonalds is the only game in town for burgers :yuck:

 

Actually I don't care. Much like people who drive hummers, you can't control other people behaviour. Oh well. I hope the burger was worth it.

 

No, I wasn't.
One family making that change is not going to 'save the world' any more than they are if they choose a hybrid.
Yes, population control is important, but so are other methods to lower the carbon footprint.
And one family will have a negligable affect. You need to attack this from multiple directions.
Society may get some people to reduce the number of offspring they have. But not everyone will do that. Society may also get some people to drive hybrids (EVs when they are available) which will also HELP the situation.


Another consideration for you. The average hybrid user in the US saves about 1.5 tons of CO2/year (from http://www.physorg.com/pdf96195136.pdf as of 2007)
That is about the per capita amount used by a resident of Costa Rica, 10 times that used by a person in Madagascar and 150 times what an individual uses in Chad. [ame]http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita[/ame]

I don't see why you seem to discount hybrids and EVs just because they are not the perfect solution.

 

The only thing that that point supports is that North Americans produce obscene amounts of CO2 - nothing more.

Anyway, having programs that limit the number of children people have would be far more effective. I'm sure I could figure out the math but I imagine that a policy that convinced a family to have 2 children instead of 3 would have the same effect as a couple thousand people switching to hybrids. The math just balances better - I don't see why people are so offended by this (of course they are and that's why environmental groups have avoided this BIG elephant in the room). Prius = Iphone - that's fine - I have an Iphone and it's techno-cool. What's the bigs deal?

 

The burger is only an excuse to get together with friends and go for a motorcycle ride. (The Paddler's Pub does have good burgers though.)

If you are referring to our recent Five Guy's excursion, then yes, the burger was easily worth burning 0.7 gallons of gasoline.


BTW, if you are so opposed to cars, why are you buying one? Why not just continue to use public transportation?

 

No offense is taken by saying that controlling population is MORE effective than driving a hybrid.
Where I take you to task is when you say that driving a hybrid or EV is negligable in it's impact.

And again, as my earlier links supported, the amount of carbon saved due to population control largely depends on WHERE that population is 'controlled'.

The math is, an average US citizen driving a hybrid saves 1.5 Tons of CO2 per year. An average person in the US, produces about 20 tons. So that would be about 13 hybrid drivers.
Now, that average was calculating a difference of 23mpg to 27mpg for the average hybrid. So if you go from an average car (23mpg) to a Prius (46mpg) that is closer to 9 tons. That would bring the comparison of 2.2 drivers switching to a Prius being the equivalent of a family having one fewer children.
Yes, population control is still more effective, but the hybrid's benefit is not insignificant.

 

While burning fossil fuels is taking energy from our past using nuclear energy is taking energy from our children, our children's children, our children's children's children, & on & on for 100,000+ years. Personally I'd rather use coal.

 

So, how efficient is urban mass transport, on average? I mean, in reality, not just making assumptions. Based on some reliable source who has actually measured it?

I had always heard that efficiency of mass transit was mediocre due to low average load factors. Buses and trains run all day and far into the night, and are only really loaded during rush hour. Cars, by contrast, only run on demand. It's not immediately clear which has higher average energy use per passenger mile, if you take the most efficient car and compare it to the average transit system.

I should note that I spent 10 years commuting to DC via the Metro, so I'm not against mass transit.

For a baseline, a Prius gets 46 MPG, and the average urban car trip has 1.3 occupants. That's 60 passenger-miles per gallon, on average.

Wikipedia lists transit buses at 27 passenger-miles per gallon, and commuter rail at 38 passenger-miles per gallon.

Fuel efficiency in transportation - Wikipedia, the free encyclopedia


Do other sources confirm the Wikipedia estimates? For example, the Wikipedia estimate for bicycling omits the calories required to generate the fuel. Maybe they goofed on city buses and subways as well.

Actually, it turns out that its Oak Ridge National Laboratories that provided the data, here:

Download Edition 27 - Transportation Energy Data Book

Going back to the raw data and recalculating, I get 42 passenger miles per gallon for rail transit and 27 passenger-miles per gallon for bus transit. So the Wikipedia article appears substantially correct.

That pretty much confirms what I vaguely recall having read. Riding on a packed train during rush hour is efficient, and riding on a packed bus during rush hour is efficient. But then, so is packing five people into a Prius. Efficient, but not typical.

The relevant measure of efficiency is how much energy it takes to run the transit system as operated, divided by the number of passenger miles you actually produce. And by that metric, transit is better than the average car, maybe, but not better than a Prius.

So, if you take a city full of Prius drivers, with no mass transit, and add mass transit that performs like the average, and divert some Prius drivers onto mass transit, then you raise total fuel consumption and C02 emissions.

But, if you are in a city where the transit system exists, the marginal pollution generated by the additional rush-hour passenger is, I am pretty sure, fairly minimal. Just like adding another passenger to a Prius adds minimally to total fuel use.

In any event, on average, urban mass transit uses more fuel per passenger mile than a Prius does. So says Oak Ridge National Labs. Whether or not you can feel good about your low incremental environmental cost during rush hour depends on how you choose to do your accounting. If you don't feel like you shoulder any of the responsibility for the transit system's fuel consumption at other time periods, then ... I guess you can feel like you have a clean(er) ride. But to me, that's like saying you get really good mileage during the "glide" phase of pulse-and-glide. In fact, the only way you can get your rush-hour ride is for the transit system to operate as it does. In that case, you really can't argue that the typical mass transit trip produces fewer C02 emissions per passenger mile than the typical urban Prius trip.

There are externalities, of course. I can't even imaging what DC traffic would be like without the Metro. But internally to each separate transportation mode, it's not clear that transit is such a winner.

 

Chogan2,

There was a chapter in State of the World 2007 that talked about "green transportation" and it detailed the figures you are looking for. I have the book in a pile around here somewhere. When I get back from my appointments I'll look it up for you.

 

F8L,

As much as I admire most environmental advocacy organizations, I try never to accept numbers presented by any advocacy organization. I'll stick with ORNL unless there is some clear reason to doubt their estimate.

Those estimates look like estimates where "typical use" is equated to having all seats filled, reading the fine print here:

strickland.ca - transportation energy efficiency (fuel consumption)

I would expect an advocacy organization to do something like that -- show how good transit could be.

If so, you have no disagreement from me on the numbers -- that is, a fully-loaded bus or fully-loaded train is quite efficient -- but that's not a measure of actual average efficiency of transit systems. Any more than 5 passengers in the car is an appropriate measure of the average efficiency of a trip in a Prius.

The ORNL data on passenger miles, by contrast, reflect the average actual experience of US urban transportation systems. They were taken from the American Public Transportation Association fact book. APTA, in turn, literally gets the data from US public transportation systems themselves. So, all of that looks pretty solid to me, in terms of gathering the census of large US public transportation systems. And reflecting actual average behavior. And, for APTA's purposes, there was no particular reason to shade the data one way or the other, and they publish it by system (so that it could be checked with publicly available information if that were an issue.)

Not having seen the data from the Worldwatch Institute, I'll bet a large sum of money that it's based on either some optimistic assumption about passenger load (like the "all seats filled" estimate above), or its based on a study or two, not the census of US urban transportation providers as was used by ORNL.

 

I can't argue against public transit for commuting, but if city buses weren't: 1) often spewing out huge clouds of black diesel exhaust, 2) 10 times too loud, and 3) half the time driven by total assholes, I'd like public transit at lot more.

 

The efficiency goes up pretty quickly as more people use public transit, plus the efficiency for others in cars would go up as there is less congestion on the roads. So if you're looking for things to promote, using more public transportation is a winner. (As opposed to more roads, for instance). That might require more options in public transit, specifically suburb-to-suburb travel.

Bike paths or bike lanes is another favorite of mine. I know the study that looks into longer life spans and increased appetite and concludes biking does not reduce carbon in the long term. However, I'm not convinced that appetites are really increased - most bikers lose weight, and they switch from endorphins from eating (which the body gets used to, and eating for pleasure requires more and more eating), as opposed to increasing endorphin sensitivity from exercise, so now you only need to eat for hunger.

Electric cars and hybrids are still complex, heavy machines that require moving a ton or more of metal to transport a payload of 1/10th or 1/20th that. My next vehicle is going to be a velomobile (enclosed recumbent bicycle) that I can use in most weather conditions and better aerodynamics than a standard rider. The standard bicycle today is based on 100 year old technology, much like the standard car is based on the ICE. A velomobile is the next step forward in practicality, just like hybrids and PHEVs are the next step for specific transportation needs truly requiring a car.

 

I'm not sure if I agree with your math but - read the summary of the report (unfortunately no english translation). Getting one million EVs only reduce the countries CO2 output by 0.1 % - sorry but that is insignificant.

If you want to go further with your math you are omitting the CO2 foot print of not actually creating the car, and all the CO2 produced throughout the child's lifetime AND it's children's (fee free to divide by 1/2 for each generation).

Comparably, EV's and Hybrids are FAR less effective at reducing the CO2 footprint than hybrids can ever be. The math isn't that hard.

 

While I don't doubt the figures, APTA is also an advocacy organization. So if you're going to take figures from environmental groups with a grain of salt, you should do the same for APTA.

 

Well, yes and no. Yes, the point is well taken. Always mistrust advocacy organizations.

But on the other hand, no. The APTA wasn't trying to prove any point with the ridership numbers. That was part of a fact book that, well, gathered facts. It was just a list of riders, trips, miles by transit system.

If anything, they'd have an incentive to overstate ridership and mileage, which would make them look more efficient. But, in fact, they published the raw data by system, so if they are shading the numbers, they can be caught. For example, they published ridership data for the DC Metro, which could be compared to what the WMATA (the DC Metro) puts out.

Whereas the point of the Worldwatch chapter is that cars are bad and other modes of transport are better. The work itself was literally a piece advocating for change.

My money is still on their having used some estimate of optimum use/seats filled (i.e., potential efficiency), not the actual observed average loading. But we'll know whether I'm right or wrong about that when F8L chimes in again.

 

A quite comprehensive book on energy including transportation can be downloaded freely here:

David MacKay: Sustainable Energy - without the hot air: Contents

It answers some of the questions posed in this thread, and the publisher (Oxford) is towards the respectable end of the spectrum.

It is not a short book, but seems worth some effort in study.

 

Most Adelaide buses run on compressed natural gas so no black fumes and less noise. We have an inner city bus which runs on solar energy.