Because ‘you never know’ what kind of expertise might be found in the forum, I thought I’d ask a question about the ‘carbon footprint’ of electric vehicles. While the vehicle itself may not emit carbon-oxygen gases as it travels down the road, how much of a bottom-line ‘carbon footprint’ was made in creating the electricity to power the vehicle compared to a high-efficiency hydrocarbon powered vehicle?

Some electricity is generated without much of a ‘carbon footprint’, but a fair portion is … what’s the ratio? (Related topic - consider nuclear waste in addition to ‘carbon footprint’)

For electricity generation, we start with either water flow (kinetic energy) or heat. If we start with heat, we then convert to kinetic energy before continuing. If my thinking is correct this process follows: kinetic to electric (some loss), electric transmission, distribution, and transformation to what the batteries will receive (some losses), electric to chemical in the batteries charging (some loss), chemical to electric as the batteries are used (some loss), and finally electric to kinetic (some loss) as the vehicle is put in motion. If the vehicle has regenerative braking, we may get some energy back in stop-and-go traffic, but for long-distance driving the recovery may be negligible.

By the time all is said and done, if I move a vehicle down the road for a thousand miles with an on-board gasoline or diesel engine of relatively good efficiency versus moving the same vehicle the same distance with all-electric power (partially generated by processes that produce a ‘carbon footprint’ and have several stages of conversion losses), how much do I gain or lose relative to ‘carbon footprint’?

Wikipedia has a very good article about electric vehicles which addresses this.

I haven't ever run the numbers on this. To be honest, I suspect that the specific carbon footprint of an all-electric car will depend largely on where it is used (and thus where it is recharged). Around here, for example, we get our power from TVA. Some of that is hydroelectric, which would represent a particularly low carbon footprint. Memphis, however, is mainly fed from a coal-fired TVA plant. Rinse and repeat that sort of analysis for any location you want. Then compare that with a hybrid's carbon footprint or some of the other alternate energy vehicles (as I recall, LP had some really impressive benefits over standard gasoline, although fuel availability makes it mainly a fleet vehicle option).

Assuming a fossil fuel power plant (coal, oil, natural gas), it's slightly less efficient to get energy to the drive wheels of the vehicle using electrical power than it is using a modern gasoline/Diesel engine. The electrical generation plant is more efficient than the internal combustion engine but the losses in transmission and the charge/discharge cycle of the batteries more than make up for it.

If you really want efficiency, look at some of the new small displacement turbocharged Diesel engines with common rail injection. They're looking at 60 mpg and more.

There's a ton of information about this on the link listed below. (In my signature.) But, sadly, there has been some heads rolling at what used to be my favorite all time start up company. They have actually fired one of the Founders so my days of cheerleading has waned. Nonetheless, the particulars, the facts and the figures you seek are still on the site.

If the facts are being truthfully represented, in a whole-context sense, then electric vehicles, despite several conversions between chemical, thermal, electrical and kinetic energy, are going to be helpful even in the near future. Hopefully by the time I’m looking to replace my current vehicle there will be several viable vehicle options and associated infrastructure available that will suit my needs well and have enough economy of scale to be available without a financial penalty.

I’ll have to check back to read the white paper ‘The 21st Century Electric Car’ when the updated version is available.

http://www.teslamotors.com/learn_more/white_papers.php

Check out this power plant in Seville, Spain:

http://www.inhabitat.com/2007/05/21/sevilles-solar-power-tower/

I read a book back in college (it was actually the textbook in an elective course on alternate energy sources) which discussed energy sources such as wind, solar, hydro, and a number of other technologies. It was an interesting read, as it talked about some of the tricky limitations of different approaches. Solar, for example, runs into a number of challenges (even before the efficiency hurdles faced by photovoltaic) because of the atmosphere. Wind really only works if you can sustain at least a seven MPH wind. It's probably a bit dated now, but I'll look on my shelf tomorrow at work and see what it's called in case anyone's interested.

Gonk: I am.

"The Almanac of Renewable Energy" by Richard Golob adn Eric Brus, copyright 1993. According to Amazon.com, it appears to be out of print but used copies may be available online.