Most Comprehensive Study Yet On Environmental Impact of Electric Vehicles

An anonymous reader writes: A few articles came out Thursday talking about the recently released report from the National Bureau of Economic Research on the environmental benefits of electric cars. The general consensus is kind of obvious -- that it depends on the ratio of coal vs. clean electrical generation that is used to charge your car. What is interesting is the extent to which it makes a difference, and that when viewed on a regional basis, there are cases where the EV doesn't do so well. And when it comes to policy decisions, it seems the central focus needs to be on the replacement of large-scale coal generation, and the rest will fall in to place. Here is one cover story from Ars Technica. Google others for varying perspectives.

Comments

Re:I see theyre using the Step 2 profit model

[JoshuaZ]

Actually, replacing coal is happening already. The percentage of plants that are coal has been going down. Moreover, the plants which are coal have been getting progressively cleaner. And as electric-plugins become more common, that means there will be more on-grid storage which will help make solar and wind more common (since one of their big problems is the intermittent nature of the power they supply). Moreover, the study uses the current crop of electric cars, where they are getting more and more efficient, and as electric cars get more efficient they'll compare more favorably in more locations.

Re:I see theyre using the Step 2 profit model

[Crashmarik]

Sure

All you have to do is quadruple your electricity prices, put in a battery system in your home to capture the "clean energy", pay more for the electric car and there you are.

lets see

http://shrinkthatfootprint.com...

Want to talk about a war on poverty, you might as well start dropping bombs on them.

Flawed research, garbage in garbage out

[Anonymous Coward]

This is not a new study and it's already been thoroughly rebuked. Here are few major flaws:

o Study considers coal plant pollution data from 2010-12. Since then a lot of coal plants were shut down (replaced by cleaner NG plants) or were equipped with filters (per EPA mandate which was recently deemed invalid by the courts but replacement mandate is forthcoming)

o Study 'forgets' to consider pollution from processing and transporting fuel.

o Some who are in the know pointed out that study fumbled the data on how green and dirty electricity is distributed throughout the grid. What study did is similar to gerrymandering where they lumped clean energy to specific areas making other ares less clean as a result.
 

Re:I see theyre using the Step 2 profit model

[Crashmarik]

Oh zap you have me

It isn't like "Green Energy" does any of those things

Chinese Rare earth mine
http://images.china.cn/attache...
Water Supply looks good

https://agmetalminer.com/mmwp/...
http://www.wantchinatimes.com/...
Nope no big honking holes in the ground there

Re:Exactly I've made this point here many times

[Rei]

I don't know where you're getting your "59-62%" figure from, it's usually higher than that. The US grid is about 93% efficient, generator-to-socket. Grid losses are far lower than most people give them credit for. Chargers are typically 92-94% efficient, depending on how fast the charge is. beyond the charger, charging is usually 90-99% efficient, depending on how fast the charge is and what sort of pack the vehicle has and pack management the vehicle does. Powertrains during operation (including battery losses) are usually 65-95% efficient, depending on torque and RPM conditions and the vehicle, with a usual operational average of 85%-ish. A small portion of the energy, depending on the type of driving, is returned via regenerative braking, which on li-ion EVs is usually 60-70% round trip efficiency (lower on NiMH hybrids). Ignoring regen, the whole picture is usually 70%-ish.

You're right about the efficiency of gasoline cars, but to be clear, it's not that the engine can't achieve higher - it's that maximum efficiency (usually 35%-ish) is confined to a narrow torque / rpm band. Gearshifting helps you pick your RPM / torque combination but you don't have control over power (the combination of the two) - that's dictated by the driving conditions. And then of course on top of that you have idling and no regen potential.

Concerning the production of electricity, it's important to note trends. Electricity is in most countries in the world, including the US, trending toward cleaner, both in regards to CO2 and to health-related pollutants. Gasoline, however, is trending toward dirtier - it involves more energy to extract and/or refine. There's no reason to expect these trends to reverse in the forseable future.

Re: I see theyre using the Step 2 profit model

[O('_')O_Bush]

It isn't like coal fired power plants have a magic mystery electricity fairy inside them.... they need rare earths as well. Coal just has tons of problems ON TOP of the problems that green energy has.

Re:I see theyre using the Step 2 profit model

[mspohr]

The NBER is a conservative funded "think tank". It gets most of its money from large corporations and people with an interest in the oil and gas industries.
This "study" is just a hit piece against electric cars funded by the oil and gas industries... it's worthless.
One example of its bias: It uses a "well to wheels" analysis of electric car energy use but for fossil fueled vehicles, it only uses the "pump to wheels" emissions, leaving out all of the energy impacts of extraction, refining and transportation of fossil fuels.