Electric Car Environmental Impact: Power Source Matters 341
another random user writes with news of a study from the Norwegian University of Science and Technology, which looked into the environmental impact of electric vehicles — not just how they do when driven, but how they are produced and by what means they are charged. The study pointed out that the production of EVs has twice as much of an environmental impact as the production of typical gas-powered cars, which must be taken into account when comparing the two. Also, they say it's important to consider the source of the electricity used to charge the vehicles. In places like Europe, where a good chunk of the electricity comes from renewable sources, EVs do indeed provide a benefit to the environment. However, "In regions where fossil fuels are the main sources of power, electric cars offer no benefits and may even cause more harm." The study says, "It is counterproductive to promote electric vehicles in regions where electricity is primarily produced from lignite, coal or even heavy oil combustion."
Re:Captain Obvious (Score:5, Interesting)
No one should have ever viewed it as the "greener" thing to do. It is/was obvious. The main benefit here is less moving parts (less maintenance) and a diversified fuel source, which should bring more stable prices.
Probably mistaken, but... (Score:2, Interesting)
LFTR (Score:4, Interesting)
Ride a bike (Score:2, Interesting)
Although it might be interesting to see the environmental impact of changing a non-bike-friendly infrastructure (such as the one here in Southern California) to one where people could/would actually ride bikes in large numbers instead of driving cars.
Re:Captain Obvious (Score:5, Interesting)
Petrol and diesel engines in cars, especially starting and stopping a lot, are appallingly inefficient. Less than 30% of the energy in the fuels gets used for moving - and then there is braking. Throw away all that good energy as - heat? Fantastic!
Electric motors are really good at stop/start - especially with regenerative braking.
Power plants are really efficient.
Also, it puts all the pollution in one place - easier to handle, yes? And better yet, it's in a place where I am not. And if I can breath more easily, I might ride my bike more. That'll reduce pollution.
Would anyone seriously bet against electric cars on a ten year time-span?
Location of pollution (Score:5, Interesting)
I have a Leaf (Score:4, Interesting)
I just leased a Leaf for 3 years. Minimal money down and $300/mo lease.
I was driving a Chevy Avalanche. I kept it because I need a truck a few times/month but was driving it every day. Now I only drive it when I need it.
I learned a lot about EVs. First, it costs me less than $0.75 for a full charge, gets me 80-100 miles in town. Compared to $150/month for gas in the truck.
Maintenance. In 3 years I will have to rotate the tires 5-6 times, replace windshield wipers as needed, and maybe replace the brake fluid once. That's it. No other scheduled maintenance.
It drives like a very peppy car. Quick off the line, good acceleration, good handling. Most of the toys are standard (cruise, navigation, XM radio, limited voice activation, ability to monitor from smartphone apps, etc).
I leased because I expect the technology to change in the next 3 years, and expect this car to be almost worthless by then, but I don't care as I can just turn it in and decide what to do then. And I will still have my truck so there will be no rush.
Is it green? Maybe. Is that why I bought it? No, I bought it to save green. We have my wife's car for distance, my truck for hauling, this is just a cheap commuter car. cheaper to own, maintain and drive.
I'm in NC, our power comes from coal and nuclear.
Bullshit (Score:4, Interesting)
Re:Effictive miles per gallon? (Score:4, Interesting)
No it doesn't. But then your car's MPG rating doesn't take into account the oil rig, oil refinery, oil tanker, fuel truck, and gas station power consumption.
Tax revenue dependency (Score:5, Interesting)
That's because people don't understand how to do taxes. Stop electing these people!
It's dumb to tax pollution as a punitive measure, or to encourage/discourage the use of certain technologies or behaviors, or to raise general revenue.
It's smart to tax pollution to offset the public-born costs of the thing which is taxed.
Don't tax pollution to nudge people into abstaining from polluting; tax them whatever it costs to clean up their mess, and then spend that money to do just that. If someone is spewing greenhouse gasses, tax 'em to plant forests (or whatever, if you have a cheaper way to handle it) of the capacity needed to bind those gasses, and then actually do that (really plant the forests).
That alone may be enough to indirectly discourage them from polluting. Or maybe they'll pay to plant the forests themselves, since they can do it more efficiently (cheaper) than government contractors. Or if they're not discouraged: don't worry about it, because you got your offsetting forest and the pollution really did get handled.
If someone is spewing something harder to clean up, then use (and set) that tax to whatever it takes to deal with it. And if nobody has the magic or tech to deal with the pollutant, then the pollution (i.e. the liability) can't be paid for, so should be forcefully prohibited, rather than forgiven (i.e. subsidized at public expense).
Don't think in terms of saving the world; think in terms of turning externalities into actual liabilities.
Dependency isn't a problem if you handle taxes this way, because you don't use the pollution tax to pay for wars or Medicare or anything else which is unrelated to the tax. e.g. If people stop dumping CO2, then your forest-planting expenses just went down, so the demand for the revenue drops at the same time the supply does.
Re:Captain Obvious (Score:5, Interesting)
You do realise this is like a report from a Saudi Arabian university proclaiming that electric vehicles will never work, right?
Re:Captain Obvious (Score:5, Interesting)
future of mobility is people moving less from one place to another, or more of them moving at once in one vehicle
Couldn't disagree more. The first option is ridiculous; moving backwards in transportation capability is the very, very last solution humans will (and should) try.
The second "solution" isn't much better; the convenience of personal transportation should be cheap & universal, not taken away from everyone for the sake of environmentalism. However, this idea could work if implemented similarly to UPS packages handling; personal transportation at beginning- and end-points, but mass-transit between major hubs.
We should only consider solutions which actually move us forward. Trying to put the cat back in the bag is silly and unnecessary.
A few points... (Score:4, Interesting)
For those interested there is a report from a few months ago on the same topic with a US centric view [ucsusa.org] (PDF warning) that comes to a similar conclusion. The main difference is Europe has much higher standards for fuel efficiency (both in legislation and public preference) so there is less potential gain for GHG emissions reduction to start with. For example:
Use phase energy requirements were assumed to be 0.623 megajoules/kilometer (MJ/km) for the EV, 68.5 milliliter/kilometer (mL/km) for the gasoline ICEV, and 53.5 mL/km for the diesel ICEV
To break this down into units most of us are more familiar with:
Electric: 3.591 miles per Kilowatt-hour
Gasoline: 34.34 miles per US gallon
Diesel: 43.97 miles per US gallon
Anyone in the US driving a vehicle made for the US market and getting those MPG figures would be justified in being a tad smug about it. Electric efficiency also seems generously high - I usually figure 3.2 mi/kWh, or pessimistically 3.0 to make the math easier, which correlates fairly well with anecdotal "real-world" reports from EV owners across the country. (5, 6 or even 7 mi/kWh is not unheard of, though these are usually your hyper-miler type drivers.)
Notable omissions from this report are include the energy and environmental impacts of obtaining the fossil fuels for either case. For example there is mention of the energy required to refine and process the metals used in battery production but no mention of the energy required to extract, refine and transport petroleum fuels. There is no mention of extraction costs for coal and natural gas for electrical production either.
There are several mentions of aluminum costs for production of EV components but having worked with both EVs and ICEVs I'm fairly confident there is more aluminum in an ICEV. Most of the engine block, come of the internal engine components, and most or the transmission body are aluminum. They are correct that there is more copper in an EV however.
Fossil depletion potential (FDP)may be decreased by 25% to 36% with electric transportation relying on average European electricity. EVs with natural gas or coal electricity, however, do not lead to significant reductions.
Nobody sensible has been arguing that EVs are magical. However, they are even at worst equivalent to what we are doing now but with the added benefit of future-proofing. A diesel engine will always need diesel, bio- or otherwise. It will always need a carbon based fuel. Always. An electric vehicle can get its electricity from carbon and non-carbon based sources alike. This means the bar to reducing fossil fuel use is dramatically lowered with the electrification of our vehicles.
tl:dr; Electrified vehicles are still a winning proposition despite not being perfect.
=Smidge=
Re:Captain Obvious (Score:4, Interesting)
You can't selectively look at only the inefficiencies of internal combustion engines in a comparison.
The best power plants (at least the ones burning coal or gas) are about 45%-60% efficient. Coal is about 33%-45%, while some of the newer gas plants are pushing 60%. Let's go with 50% as an average. That's being rather generous since the vast majority of the world's electricity comes from coal. But the short-term trend seems to be more emphasis on gas (gas and oil have picked up the slack since nuclear fell out of favor after Fukushima - hooray short-sighted fear mongering).
Transmission losses over power lines are on the order of 1%-3%. So call it 98% efficient.
Charging losses are the big one. The faster you recharge a battery, the more of the energy is converted into heat instead of stored chemically. This puts EVs in a catch-22. They need to be charged quickly overnight (relative to capacity) if the vehicle is going to be used daily. But if you charge them too quickly the drop in charging efficiency defeats the purpose of using an EV instead of an ICE. Real-world charging efficiency of the Tesla Roadster is about 80% [futurepundit.com]. If you use a quick-charger as advocates suggest to get around the range problem, that can quickly plummet to 50% or lower. For this reason, the most likely long-term solution for "charging" batteries on a long trip will simply be to swap out the battery pack for a pre-charged one. As you'll see, if you rely on quick charges you end up less efficient than an ICE.
I'll assume discharge losses are zero. Discharging also generates waste heat too, but I can't find any real-world figures on this for EVs. I'll assume the large capacity relative to the load in an EV keeps this to a minimum.
Electric motor efficiency is about 90%-95%. Yes they can hit 97%, but those are typically found in laboratories, not mass production vehicles. Efficiency drops at lower load, but let's ignore that since a similar thing happens with an ICE.
An ICE's automatic transmission (torque converter) can hit 90%-95% efficiency. Yes, blew me away the first time I learned that considering it's just fluid squirting onto turbine blades. But ~75 years of R&D has brought it a long way.
After the motor and transmission I assume the EV and ICE vehicle are the same in terms of energy losses. You could argue the EV weighs less, but then you're talking about something with an extremely short range. The Tesla S model with ~300 mile range weighs as much as an SUV (4900 lbs). Wheel, friction, and aerodynamic losses are pretty much the same.
So what's the final tally?
ICE = 30% * 90% = 27% efficient
EV = 50% * 98% * 80% * (100%) * 92.5% = 36% efficient
So yes the EV is more efficient overall, but it's not that much better than the "appallingly inefficient" ICE. For EVs to really shine, we need to move away from fossil fuels for electricity, and shift to nuclear and renewables. (Incidentally, a similar analysis for hydrogen drops its efficiency down near ICE levels. Factor in the enormous difficulties of transporting and handling hydrogen fuel, and until nuclear and renewables generate the vast majority of our electricity, hydrogen fuel cell powered cars simply aren't viable.)
Regenerative braking helps, but you can put it on an ICE too (aka hybrid). It only recaptures about 30% of the vehicle's kinetic energy, so strategies like timing lights so cars hit fewer reds, keeping your speed down (kinetic energy goes as the square of speed, so stopping from 60 mph wastes nearly 80% more energy than stopping from 45 mph), and constructing good freeways and freeway access can be as or more effective at saving energy.
Re:Tax revenue dependency (Score:4, Interesting)
But it is even dumber to tax income and payrolls. We have to tax something, and all taxes have the side effect of discouraging what is taxed. But taxing pollution results in less pollution, while taxing income and payrolls results in less productivity and job creation. Which is worse?
Citation provided (Score:3, Interesting)