Electric Cars and Their Discontents 348
A typical comment about the global impact of switching from gasoline to electric cars on a wide scale comes from reader dbIII, who comments:
"Until something replaces Coal power plants as the main method of generating electricity, you're just replacing one evil for the other."
"With better battery storage it doesn't matter much where the electricity comes from and when - the car could be charging up with solar power in the carpark in the day or with wind when it is blowing, or off-peak when the base load stations are running as low as they can but no-one wants to use the electricity."
"Battery power isn't about saving energy anyway, it's often about shifting the pollution to a big facility that can handle it instead of having heavy pollution control equipment to move about. The first hybrid car I saw, back in 1987, embodied this principle and was designed to work at an underground mine. Above ground it ran on fuel, but below ground you wanted to minimize the air pollution as much as possible so it ran on batteries."
The continued existence of the earth as a habitable planet aside, what about the car itself, and in particular its power source?
Jah-Wren Ryel has a quibble with the terminology used the linked article, writing
"This car is not a true Tesla Car. If it were, it would have no batteries at all. Instead it would gets it energy from some kind of wireless source like microwave power transmission or even the Earth's magnetic field."
Many readers worried about exploding batteries; glowworm was "left wondering if this car is involved in an accident if the batteries will vent like the recent Slashdot articles suggest. Exploding Dells, fires on planes, and soon at an intersection near you... cars venting more flame than the Batmobile."
Reader nSinistrad_D provides reason to think such explosions are unlikely:"Looks like the company that is manufacturing the batteries has replaced graphite with a 'Lithium Titanium Oxide' that they've tested and claim doesn't have the smoking, venting, or explosive problems of normal lithium ion batteries. Here is a link to a rather informative article about the battery technology that will be used in the Tesla. ... I mean, based on the stuff I've read about the founders of the company and a lot of the people who have invested in it (i.e. Elon Musk, Larry Page, Sergey Brin, etc.) I feel I'll wait and see before passing any judgement."
Reader artifex2004 is skeptical: "Here in Texas, where I suspect temperatures exceed battery design, I think this idea will bomb spectacularly. Seriously, though, Li-ion? I shudder to think of how those will get disposed of, eventually."
And Reader Moofie has a tongue-in-cheek solution if the batteries ever go critical: "Maybe you could design a clever little nozzle to get a boost from your on-fire battery packs. That'd be AWESOME."
It's not just safety, of course, that matters to drivers, but practicality for other reasons:
Reader iamlucky13 writes: "15 minutes on the charger might get you another 15-20 miles. And 220 volts at 70 amps is a pretty hefty 15 kilowatts, so to have a dozen cars sitting at the local McDonalds charging is going to be draining about 180 kW from their coinpurse. That is a serious amount of juice. Also, I'm skeptical that you'll be getting 250 miles at 70 mph. If I remember right, electric motor efficiency and power typically increase with load, but fall off with speed, which makes them awesome for say, a 0-60 run in 3 seconds, but marginal at best for high speed cruising. That 250 mile range estimate is probably at significantly lower speeds."
"Big rigs generally run around 5 mpg, but it varies quite a bit around that number depending on the truck, the load, and the speed. Few truckers drive at the most efficient speed because it increases the labor costs significantly."
"If you're suggesting running commercial trucks on electricity, forget it for the foreseeable future. It's definitely been considered. Not only is there the conflicting speed issues I mentioned above, but you run up against the energy density limitations of batteries fast. Assuming the numbers from the article are correct (I doubt it...something isn't quite adding up according to my gut) and unrealistically taking the charge/discharge at 100% efficiency, it's storing up 194 MJ. Gasoline holds about 120 MJ/gallon, so the 1000 pounds of batteries (according to the Tesla website) are equivalent to about 1.5 gallons of gas (6.3 pounds/gal). Divide that an efficiency of around 30% and you've got a 32:1 energy density ratio in favor of gasoline. For a truck to haul the equivalent of 150 gallons of fuel (actually diesel, not gas, but close enough), it would need about 30,000 pounds of batteries. But then you have to go farther and take into account that 2/3's of its cargo capacity has been replaced fuel, so you need to make 3 times the number of trips. And you've got a lot of trucks either sitting idle recharging or having their 30,000 pounds of batteries swapped out every few hundred miles."
"Obviously these are really rough numbers, but other engineers have already looked at the idea in more detail and rejected it."
"I'm not trash-talking the Tesla. It looks like a lot of fun, but like all sports cars, it's a toy and not a good comparison for commercial trucking. Most of a car's weight is itself, be it gas or electric. Most of a truck's weight is it's cargo."
"For the record, I think electric can work extremely well for short range commuting (5-10 miles on city streets), but if you travel far, you'll realistically be looking at gas."
As to the exact number of batteries in the car, reader wbean provides a good reason why it should be exactly 6831: "The motor is going to need a lot higher voltage than a laptop. This means that the batteries have to be organized in series/parallel banks. 6831 is a plausible number since it is 23 x 11 x 3 x 3 x 3. This gives you a lot of flexibility in arranging the banks. You could have 99 banks of 69 batteries in series, presumably giving you something like 345 volts. That sounds about right for a DC motor."
Of course, battery technology is the real crux of the issue; balancing safety, weight, volume and energy density is a tough problem, and as reader loose electron puts it,
"Whoever comes up with a significant advance in battery technology will . Li-Ion batteries have excellent amp-hour ratings for their size, but like all other batteries are still pretty limited."
"Acceleration/Torque for electric cars is not a problem. High performance capabilities are there if you want them. However, you are playing battery energy against performance against distance, and all electrics, or fuel-electric hybrids have been designed to be 'green' in their approach. (Any Hummer owners want an environmentally aware vehicle?)"
"Right now the weakest link in many electronic systems is the energy source. A good solution there and you can be a very wealthy person."
hotspotbloc suggests " a different type of hybrid," one with:- "enough batteries for ~50 miles.
- a small (100cc) biodiesel engine running at a fixed and preset RPM connected to a small generator. The engine would be set to run at the peak of its power curve.
- a small ~10L fuel tank
- and
- an AC charging circuit"
"This is a really old idea. I saw something like this (on a much larger scale) on an USCG cutter (WLB-389) that was built in 1943. Two diesels -> two generators -> one electric motor. Worked great and it could double as a light ship."
Finally, several readers' comments focused on the merits of the particular electric car, rather than only as the embodiment of its constituent technologies.
fermion was one of a handful who talked about the car as a sportscar per se, writing:
"I would wager that this vehicle is more like a Lotus Elise, or a Corvette, or even a S2000, all of which can be had for under 50K. Any performance benefits over those sports cars can be attributed to the natural advantage of this car, namely that you can go from 0-60 without switching gears, and it is easier to get it perfectly balanced without an engine. Anyway, The true test of a sports cars, as opposed to just a fast car, is the handling, which was not mentioned in review. Without proper handling, it becomes a Mustang at 30K."
"Which is to say we are still in the same world, in which low volumes and other issues cause electric cars to be 50%-100$ higher than traditional cars. All that seems to have happened here is that an electric car has been targeted to the high end market and priced accordingly. It is kind of like taking the hummer, putting a cheap truck base on it, calling it an H2, and pretending that it still has the dubious value of the original."
"Oh well, I suppose if they can build a sedan for 35K I would be impressed. We would also have to look at maintenance cost of the vehicle, which would be dominated the battery replacement. A sports car car easily run 20 cents/mile in maintenance. Knowing that laptop batteries can only handle a couple hundred charge cycles, one can image where the long term maintenance cost could approach three or four time that amount."
"I wish we had electric cars. I think the technology is there, and the pricing could be reasonable. But even companies that could be using the electric car to revive themselves, for instance Mazda and Ford, still seem to be married to the antiquated internal combustion engine."
ChronosWS largely agreed with this, writing that "cars like the Porsche Carerra and the Bugatti Veyron (mentioned in a related article) are consummate sports cars -- they exemplify not only speed but styling, handling and quality expected of a car with their price tag. Cars such as the Corvette, especially the most recent incarnation, do so relatively inexpensively. But regardless, 0-60 acceleration is not the most important statistic, and often isn't an important statistic at all except to people who don't know better (I refer the undereducated to the more useful 0-100-0 or 0-150-0 tests, as well as relevant agility tests such as emergency lane change, slalom and skid pad.) Electric cars will be desirable when they meet the following conditions met [by] existing cars:"
- "price (under 30k)
- features (styling, interior, gizmos)
- convenience (fueling in under 5 minutes)"
Thanks to all the readers who took part in the conversation, in particular those quoted above.
Re:I'd like to see more of these (Score:5, Informative)
Compare that to the 2006 Toyota Camry V6. 268 horsepower (under the same SAE standard), a several hundred pound weight disadvantage, and EPA mileage 22/31 on 87 octane fuel. The Chevy Corvette weighs 200 pounds more than the RX8 and has a huge 400 horsepower V8, and its EPA mileage rating is 18/26.
Now, Toyota can chew up Mazda and spit them out with the amount of money Toyota spends on research and development each year. So it's at least possible that future research will product Wankel rotary engines that offer superior power and efficiency versus piston competition. But right now, there's no efficiency advantage to the Wankel.
Re:wow.. talk about naive (Score:1, Informative)
A battery powered car, an ecar if you will, judging by the price is much more expensive in environmental terms, as well as monetary terms. The environmental cost of producing the exotic materials used to manufacture the batteries in a ecar might outweigh any advantage they have (of course that cost will/may decline). An ic powered car is relatively cheap to produce in comparison, with only the some of copper, a few magnets here and there, and steel.
Your argument about the efficiency of a power station compared to the average car in terms of its maintenance and the driving style thereof is completely spurious. Will all the ecars be maintained to peak efficiency and driven in a style that optimises their mileage? Of course not.
The best bet is biodiesel, it seems to me. Use the power of the sun without the massive drain that making enough ridiculously exotic batteries to power all the cars in the world. That may be naive in terms of how much agriculture would have to be turned over to supplying gas instead of food, but don't we have a food surplus anyway?
You are naive to listen to and to entirely swallow arguments for centralised power generation, but it is human nature to ignore those with whom you disagree. I'm sure all these arguments were made in the main body of the
Re:Reality: Some of us don't use coal or oil (Score:4, Informative)
Hydroelectric power generation is renewable, however, all forms of power generation involve side impacts, such as siltation (the buildup of silt behind dams, which must either be removed (used for topsoil replacement, especially in alpine soils) or further dams built (a method used in a number of countries to build flat farmland areas), salination impacts due to irrigation (which can be reduced by drip irrigation and time-sensistive irrigation (don't irrigate when it's hot and sunny)), etc.
Hydroelectric energy is generated by turbines which are moved by the water cycle - which is primarily powered by snow/ice that melts, flows into rivers, powers the turbines, goes to the ocean, and in all forms of usage is evaporated (unless split for fuel cell energy storage or chemical usage) to return to the cycle - a less reliable method involves the lack of snows, but this requires large cachement basins and is less efficient.
Every form of energy creation involves inefficiencies and transmission reductions. Batteries involve the use of specific metals and other destructive methods, which involve smelting (something I've done on a large scale at Tek Cominco) as well as alloys (ditto).
Now, there are fish impacts, but from an energy perspective, that is a side effect, not part of the actual energy creation process. Coal involves a number of destructive and humanly dangerous methods in its usage as well (which I can attest to, due to experience in mining and ownership of Peabody Coal IPO shares).
Next time, let's not pretend that up is down. Heck, the solar radiation that drives this entire process comes from a finite source, the sun, which will expand and absorb the Earth way before it runs out of energy, but our seas will boil over before that day.
Re:Bad link (Score:3, Informative)
Nation wide, we use about twice as much power for transportation as is delivered through the electrical system. There's nowhere near enough slack in just hoping that people only charge their cars during off-peak hours. Could we sneak in a few electric cars? Sure, but we've already exceeded the engineering margins on the elecitrical power distribution infrastructure on the East and West Coast grids, and adding more load is really going the wrong direction, given our apparant willingness to accept blackouts (rolling or otherwise) instead of building more infrastructre.
Further, chemical batteries are useless for freight hauling, and ignoring 18-wheelers when considering problems with oil would be a big mistake these days.
Anything but coal -- yet even if you assume that EVs are charged only coal-fired plants, you're still in much better shape than you are burning gasoline in cars.
This is very wrong. From a CO2 perspective, coal-powered electric cars are about 5 times as bad as buring gas in cars. From a pollution perspective coal is also worse than any modern car, though it has the questionable advantage of dumping the pollution somewhere that doesn't bother the driver of the car.