EVs vs. Gas-Powered Cars: No Ride to Utopia

Hey Mr. Green,
Is an electric car really more efficient than a hybrid getting 50-plus miles per gallon running on gas? How efficient (and green) can it be to charge an electric car with natural gas or coal-based electricity, when we lose roughly 66 percent of the original energy in generation and transmission? –Keith in Boston

Hey Keith,
Once a gas-powered car gets around 45 to 50 miles per gallon, the energy it consumes decreases to about the same amount of energy needed to propel an electric vehicle, or EV, of the same size.  But as you indicate, that’s no reason to get all cheerful and start believing that EVs or super-efficient gas cars will save the world. They won’t. Alas, they might even hasten our ruin by promoting the illusion that more-efficient cars are “good for the environment.” I don’t care how many times T. Boone Pickens comes on TV to peddle this fantasy—he’s wrong. The best you can say about the most efficient car is that it is less of an environmental menace than a gas-guzzler.

Now if you must have a car, an EV is the best choice. But this does not absolve EVs from the terrible environmental damage that will continue as long as cars remain our primary mode of transportation, instead of what they should be: neat toys for special excursions, racing, and antique shows and sites for torrid romantic encounters. If you want to find out why, read on.

The Truth About Safety, Size, and Saving Gas

Hey Mr. Green,
Why do today's subcompact cars have such poor fuel economy compared with those made 20 years ago? Some people claim that safety requirements have added weight and lowered gas mileage.
--Robert in Wallkill, New York

Hey Robert,
U.S. automakers turned to power and speed because there's more profit in a big, fast luxury model than a rinky-dink Lynx or Sprint. Claims that safety rules add significant weight are wrong. By 2001, they had boosted weight by an average of only 125 pounds--less than some drivers have gained since Ralph Nader started hounding Detroit to make safer cars in the '60s. Air bags, seat belts, head restraints, electronic stability controls, and smarter frame designs don't weigh a whole lot.

Podcast: Driving to the farmer's market

"Hey Mr. Green: There's a farmer's market 12 miles from our house, and a supermarket just 1.5 miles away. Does the 24-mile round-trip drive to buy local produce make more environmental sense than a 3 mile drive for produce that's not nearly as local?"

Click here to listen to the answer! You can also subscribe to Mr. Green's podcast.

Thinking Outside (and Inside) the Car

Many environmentally minded folks prefer to buy meat and produce from local farmers, for a number of good reasons. Dealing directly with the grower makes it easier to encourage and support farming practices that conserve the soil, require fewer chemical fertilizers and pesticides, or are completely organic. Also, probably less energy is consumed overall than when food is shipped several thousand miles.

Unfortunately, for many shoppers “local” isn’t all that local. Quite often the nearest farmers market is 25 or 30 miles away. So, readers have been asking if a weekly trip is justified, or if they’re undoing the benefits of local food by driving so far. Not to mention that $4- or $5-a-gallon gas might make virtuous food unaffordable for some consumers. 

To deal with this, the more Spartan among you have pledged to make the trip by bicycle instead of car to conserve energy. I wholeheartedly support this combination of a triathlon training program and a shopping trip, but there are two less strenuous solutions:

1. Take fewer trips--and buy a large volume of whatever is in season. Then can, dry, freeze, or preserve what you can’t eat fresh.
2. Carpool. Well, duh. A no-brainer I never even thought of; it was a reader’s idea. Yep, even those of us who don’t own cars are still locked into the idea of solo driving to the store and to work.

So if you bring several people with you (who would otherwise drive separate cars), the fuel problem becomes much less significant. Have a festive trip. Catch up on gossip, argue politics, discuss methodologies of produce preservation, and take a break from e-mail and text messaging to experience the joys and sorrows of personal communication! And while you expound on the advantages of Slow Food, be sure to drive slow to save more gas.

Affordable Electric Cars

Hey Mr. Green,
Is there a practical electric car a person of moderate means can buy and operate? --Kent in Sherman Oaks, California

If by practical you mean an ordinary family car, I can't recommend anything except stealing one of those electric models--like Toyota's RAV4 EV--from the handful of lucky souls who acquired one before the auto industry quit making them. (That sad story was best told in the 2006 documentary by Chris Paine, Who Killed the Electric Car?)

Otherwise, you could order a Tesla Roadster for $100,000, but that might be a bit beyond your price range. You can explore a number of small, get-around-town models at the Electric Auto Association's Web site (eaaev.org/eaaevsforsale.html). The other option, if you are mechanically inclined and have a lot of time on your hands, is to retrofit a standard car with an electric motor at a cost of around $10,000, plus 200 to 300 hours of toil rigging it up. The EAA site can lead you to suppliers.

The Error of My Ways

We received a deluge of comments about my response to the false proposition that it takes more energy to make and ride a bike than to make and drive a car. Most heartily agreed that any idiot can see it takes less energy to move a 35-pound bike than a 1.5-ton car. Some pointed out the health benefits of cycling; others brought up shining examples of commuters who have logged thousands of miles biking to work. Some said it was idiotic to expect people to commute by bike, and some just said everybody involved in the discussion was an idiot.

The smartest readers caught a very embarrassing error. I said, wrongly, that it would take only the amount of energy in a half-pint of vodka to provide enough calories for a cyclist to pedal 48 miles. The fact is, it would take about a quart of vodka. I simply misread the USDA's nutrition data chart. The only and quite feeble excuse is that the misreading may have been caused by rigid enforcement of my paperless office policy--reading on-screen, no matter how big you blow up the text to combat presbyopia, does seem to propagate errors. (By the way, the USDA’s National Nutrient Database is a wonderful and sometimes surprise-filled source of information on food.)

Despite that mistake, the main point--that you're better off drinking ethanol and burning it by pedaling than by running an engine--is still valid. As noted, it would take about two gallons of pure ethanol to propel the average car the stated distance. This means the biker is 16 times more efficient than the driver (since a quart of vodka only contains a pint of pure ethanol).

Finally, while it's obviously crazy to expect people to commute 30 miles or more by bike, it's not impossible to get into a carpool. Carpooling may not provide the exercise celebrated by many readers, but it does go a long way to reducing commute costs and energy use. You can search for ride sharers at eRideShare.com or one of the many sites that offer carpool info. Let me know if it worked out for you.

Mr. Green is busy on his world-wide publicity tour for his new book. In the meantime, here's a Mr. Green classic column from March 2007.

Hey Mr. Green,
Please explain how carbon dioxide emissions are measured. I find it hard to believe that 2,000 pounds of CO₂ are emitted per passenger for a round-trip flight from Los Angeles to New York City. —Heath in Calabasas, California

Your perplexity probably stems from the way the units are stated. As I explain below, it only takes 100 gallons of fossil fuel to make 2,000 pounds of CO₂. So for the approximately 5,000-mile cross-country round-trip, an airliner averages about 50 miles per passenger per gallon--way better than you'd get driving all by your lonesome in most cars. Plus, you're only subjected to two airline meals, as opposed to a dozen fast-food stops.

Now for the math. Atomic behavior isn't always intuitive, as the chemistry of combustion reveals. A gallon of gas or jet fuel weighs 6 to 6.5 pounds, about 5.5 pounds of which is carbon. When an atom of carbon burns, it joins up with two atoms of oxygen to produce CO₂. Although carbon seems like the heavier part of this equation--it's a hefty ingredient in everything from coal to tennis rackets--oxygen has 1.33 times the atomic weight. Therefore, the two oxygen atoms in carbon dioxide are 2.66 times heavier than the original carbon atom. So your initial 5.5 pounds of carbon combine with 14.6 pounds of oxygen to give you 20 pounds of CO₂. Call it intelligent design or confusing design or unfathomable design, but that's the way it is.

Mr. Green is busy on his world-wide publicity tour for his new book. In the meantime, here's a Mr. Green classic column from June 2007.

Hey Mr. Green,
I usually get 47 to 50 miles per gallon on my 2005 Prius and pay between $2.50 and $2.75 per gallon for gas. Is it cheaper, or better for the environment, to charge gadgets like my cell phone, iPod, and laptop in my car or in my house? I'm in the car about two hours a day. —Joe in San Francisco

I could be lazy and simply tell you to worry less about your toys' relatively small energy use and more about their toxic guts and batteries--and to make sure you safely recycle them. But this is such an intriguing question I couldn't resist poking around for an answer. Though off-the-grid energy production appeals to Americans' do-it-yourself spirit, it turns out that a gasoline engine is not a very efficient device for such efforts.

Using your Prius to charge your cell phone will cause you to emit about 80 percent more carbon dioxide than plugging in at home. (The cost is slightly higher too.) There is, however, one exception: You can get "free" energy if the car's battery is fully charged and the braking system is generating enough power so that the gasoline engine doesn't have to run the alternator to charge the battery. Though this is generally not the case, it might occasionally occur as you roll down the famously twisty Lombard Street or one of your city's other steep hills.

Get on the Bus

Mr. Green is busy on his world-wide publicity tour for his new book. In the meantime, here's a Mr. Green classic column from August 2007.

Hey Mr. Green,
My biggest peeves with our school district are its irresponsibility with money and its poor priorities. Within the last bunch of years, the district rebuilt and renovated all its schools--the high school, the junior high, and eight elementary schools--built a new administration building, Astroturfed the football field and rubberized the track, and put a totally new HVAC system in the high school. Yet nothing was done regarding traffic flow.

Although busing is mandatory for kids in the third grade and below, students at the junior high and senior high must live two or three miles, respectively, from the school to get bus transportation. No city bus passes are provided. Hence, many parents transport their kids by car. The traffic is horrendous, and the amount of gas being wasted on a daily basis is even worse. Think there's a little hole in the ozone layer over our district? --Sue in Rochester, New York

Hey Sue,
I don't blame you for being upset. Of course, if I were running the district with my green iron fist, I'd require all those lazy, pampered kids to walk or bike to school, like in the old days.

They'd probably shed more of their junk-food-and-soda blubber with that routine than they would shuffling around the freshly rubberized track, and they'd be having creative conversations and flirtations on the way home instead of getting to the couch quicker and snacking away while stunting their little brains with TV, video games, or the institutionalized narcissism of MySpace.

However, since such a healthy reform would be considered child abuse in today's overmonitored world, I recommend that you estimate how many total miles parents have to drive to haul the kids to school. Then multiply the mileage by 52 cents, which is the average cost of car operation according to the American Automobile Association. Next, compute the total time parents spend on these daily trips during the school year, and multiply it by the average hourly wage in your town. Then add these two amounts and compare them to the cost of extra school buses, drivers, and fuel.

I don't know what result you'll come up with, but I have a strong suspicion that the price of individual car transportation--including both operating costs and time--will greatly exceed that of buses for these kids. People are often amazed when presented with the hidden costs of automobiles--and that's not even considering the health and environmental toll of the emissions from all those traffic-clogged cars.

If you aren't inclined to dig up the data and make these calculations yourself, then you should demand that the school district's bean counters do so. Given the amount of money they've been allocating, they must know something about number crunching, even if they're doing it as recklessly as you say. If the numbers work out like I think they will, the next step is to use this data to lobby the district to make buses more widely available.

Environmentally,
Mr. Green

Enviro Cost of a Bad-Hair Day

Hey Mr. Green,
I was at a bar the other night with a friend, and we came up with a question we thought you might be able to answer: How many households would need to exchange their incandescent bulbs for compact fluorescent ones to compensate for one Hollywood celebrity flying cross-country in a private jet to get a haircut by his or her favorite beautician?
--Nelson in San Francisco

Finally, a celebrity question more meaningful than "Is Angelina pregnant again?" or "Will Britney get her kids back?" Assuming that the star has a midsize charter jet and takes eight or nine groupies along for a 2,500-mile ride (roughly Los Angeles to New York), his or her share of jet fuel burned would be about 175 gallons, or 22.6 million British thermal units (Btus). Since it takes about 10,210 Btus to make a kilowatt of electricity, the flight would use up the equivalent of 2,214 kilowatt-hours of electricity.

Because a 25-watt fluorescent bulb is four times more efficient than an incandescent one yielding the same amount of light, the fluorescent will save 600 kilowatts in its 8,000-hour lifetime. Therefore, you'd only have to buy four fluorescents to save the energy required to fly the celebrity to the beautician. Amazing but true. Actually, let's make that five fluorescents because there's obviously a lot of energy squandered hauling his or her celebrity ass to and from the airports in a 15-mile-a-gallon limo. And that's not even counting the energy consumption of the paparazzi and media acolytes, which would change the equation considerably.

But time is also a big factor. The above calculation reveals the energy savings for the life of the bulb. If you want to know how many fluorescents you'd have to buy to compensate for the energy wasted for the duration of the celebrity's flight, the number changes dramatically. At a cruising speed of 540 miles per hour, your speculative celeb would be airborne for about five hours on the trip. In that time, a single fluorescent bulb would save only 0.375 kilowatts. So you'd need about 5,900 fluorescents to make up for the energy consumed on that particular flight. The beauty of this is that you can spin the argument either way, depending on how you want to package it!

And whether you buy four or 5,900 fluorescents to offset your favorite celebrity's flight, remember to recycle those bulbs when they die out. Since they do contain toxic mercury (albeit a small amount), that's the only way to truly lighten the burden of the environmental guilt he or she doesn't feel anyway.
Environmentally,
Mr. Green