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

Economic factors are my priority

[ranton]

Its a good thing my reason for wanting hybrid and electric vehicles is purely economical. Environmental benefits are a nice side effect in many cases, but the reason I want my country less dependent on oil is almost purely to reduce foreign dependency. Money spent buying coal from West Virginia stays in our economy, while oil bought abroad does not. Also electricity produced by coal is less expensive per mile driven than gasoline, so that allows money to be spent on more productive areas than natural resources.

The environmental benefits are still important, but dealing with dirty coal is a separate issue from electric cars IMHO.

Re:Economic factors are my priority

[beanpoppa]

Even if our electricity today doesn't come from predominantly green sources, moving to an electric automobile fleet allows us to more flexibly power our cars. ICE engines confine you to fossil fuels, methane (which can be green), and hydrogen (in the most inefficient way to use it...) Electric cars can use any of these power sources in the most efficient way, as well as solar, wind, geothermal, whatever. We need to overcome energy storage, recharge time, and cost disparities to meet performance parity with fossil fuel ICE's, but having an electric automotive fleet is good for society, even if only 13% of our electricity currently comes from renewables.

Re:Economic factors are my priority

[im_thatoneguy]

Yeah, I'm surprised that computer geeks don't more broadly embrace electric vehicles based solely on the principle of flexibility.

Electric cars far better embody the Unix philosophy of atomization and portability than ICEs do. If you're in the woods you could trickle charge your car off of solar. Or you could put a turbine in a stream and power your car from a creek, or you could hire a few people on bicycles to pedal away for a couple days to charge it up, or you could setup a wind turbine, or you could have a small ICE generator burning gasoline, or you could have a generator run from nuclear power, or you could have a generator run from a wood fire or coal or anything.

The beauty of electricity is that it's a common currency just like text is to a unix application. You don't mandate an energy source you can mix and match and switch power sources dynamically.

Electric vehicles are also simple and easy to understand. Electric motors have pretty much the one single moving part. Even battery technology is modular, you could have an electric car that has no batteries, just an ICE generator in the trunk providing electricity.

From a form factor perspective it should also appeal to computer geeks' ideals of Aesthetics. A design in which you might need wheels, but otherwise the sky is the limit on where you place critical components.

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.

Now there isn't even an article to read ?

[Crashmarik]

Seriously a paywalled report and a jackass going google it ?

Re:I see theyre using the Step 2 profit model

[Rei]

Why are we dignifying it by calling it a "study"? It's not published in a journal. It's not undergone peer-review. It's a "working paper" on the NBER website. It's not the same thing. If it was legitimate, they would have submitted it to a legitimate journal and gotten it published. They have not, as it stands.

How long is it going to take for news sources to bother to check whether something has undergone peer-review before they start citing it as "science"? Let alone the "most comprehensive study yet"?

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

[Ol Olsoc]

"Study" does not mean peer reviewed science research.

Re:I see theyre using the Step 2 profit model

[PopeRatzo]

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.

Whereas with coal, all you have to do is tear great big holes in the ground, destroy the water supply, kill thousands of miners with black lung disease and untold thousands more with pollution, contribute to climate change and have the government subsidize the whole thing.

And there you are.

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:"Replace large-scale coal generation"? With WHA

[Smidge204]

And it's not just replacing current electrical generation - there would probably have to be a two or three ORDER OF MAGNITUDE expansion of electrical generation capacity.

100 to 1000 times more electricity? Really?

2014: 136.78 billion gallons of gasoline consumed.

At 33 kWhr/gallon, that's 4,514 billion kWh if you completely ignore any differences in efficiency.

2014: 4,093 billion kWh of electricity produced.

So at the absolute WORST case, it's a little more than double. But when you figure that an electric vehicle uses that energy nearly three times more efficiently, it's under 50% more.

And that's if you go ahead and replace *everything* that burns gasoline with electric, which of course you wouldn't.

Then after all that, producing ~50% more kWh does not translate into needing ~50% more power plants. You would need to factor in some diversity factor as not all power plants are running all the time nor at full capacity.
=Smidge=

Re:I see theyre using the Step 2 profit model

[michelcolman]

Yes, just a few weeks ago an article was posted here on Slashdot saying that the amount of electricity needed to pump up, refine and transport gasoline is about the same as that consumed by an electric vehicle for the same distance. So when you have finished filling up your gas tank, you have already used the same amount of electricity as the electric car and you haven't even started burning the fuel yet. Did this "study" take that into account?

Add to that the fact that pollution for electricity generation normally happens outside population centers. You should see the smog produced by cars in front of my kids' school on a foggy morning. I can't wait for all cars to be electric.

Re:I see theyre using the Step 2 profit model

[ShanghaiBill]

All you have to do is quadruple your electricity prices

No. Coal is mostly being replaced with natural gas, which is cheaper than coal, and generates half the CO2. Gas moves in pipelines, which are cheaper and safer than the trains that carry coal. Gas turbines are more efficient than the steam turbines that coal plants use. Gas burns clean, and doesn't require the expensive pollution abatement equipment required by coal.

It no longer makes economic sense to build coal plants in America. Most new projects have been cancelled or suspended. Gas is cheaper and cleaner.

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.

Fundamentally flawed

[JDG1980]

If you're going to take into account the whole supply chain for electric cars, you have to do the same thing for gasoline cars. This study doesn't do that. It calculates the CO2 cost of electricity generation for electric cars, but assumes that gasoline just magically shows up at the pump and doesn't incur any environmental costs in getting there. The CO2 emissions resulting from extraction, refining, etc. are completely ignored.

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.

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

[Ecks]

That 93% efficiency is the ratio of watts arriving at the socket over watts generated at the plant. The watts "lost" between those two places are lost heating up the transmission lines. The 59 ~ 62% figure is the ratio of watts of electricity generated at the plant over BTUs of heat generated by burning fuel to heat water and create steam. Systematically, the 59 ~ 62% is more important.

Key to the discussion is the fact that energy comes in two forms: "heat" and "work". Heat is thermal energy. Work is the energy of motion or electricity. In layman's terms we usually don't differentiate between a "motor" and an "engine" but that difference is also very important here. Technically, a "motor" converts work into motion and an "engine" converts heat into work.

In the system that is an electric car powered by a remote power plant:

• The heat comes from burning fuel at a power plant to create steam;
• Passing the steam through an engine, a turbine causes the turbine to spin; this creates work;
• The spinning turbine drives a generator converting work of motion to work of electricity;
• The electricity travels over power lines to batteries in a car;
• Later, we throttle the stored electricity from the battery through an electric motor to create motion.

Thus the overall fuel-to-motion efficiency of an electric motored car is: (59 ~ 62%) * 93% * battery_efficiency. Battery efficiency of Li-Ion batteries is well above 90% if I recall correctly. But assuming the worst, electric cars are at least 49% fuel-to-motion efficient.

In contrast, the fuel-to-motion efficiency of a car powered by an internal combustion engine hovers in the 35% range today due to market constraints on cars.

Note well that this analysis is generous to internal combustion engine automobiles because it does not account for the difference in energy cost for refining crude oil into typical automotive fuels like gasoline or diesel.

Re: Commit to puchasing 100% green energy when buy

[WindBourne]

actually, no. Basically, those 'clean' companies sell their electricity regardless if you 'buy' from them or not. Think back about 10-15 years ago when every ISP was selling you DSL. They would claim that it was THEIR DSL, and not the RBOCs. Of course, it was a lie. Basically, the electrons ran through RBOC's systems.

The ppl that 'pay' for clean energy from other sources are no different than my solar system. I have 43 panels on our roof. We generate 9.8KWs. And when we buy our Tesla shortly, it will HELP charge it. BUT, the reality is, that most of the electrons charging it will be from nighttime, not daytime. As such, my solar system lowered my costs and helped with daytime electricity, but my charge will still be coming mostly from the grid, which is still around 36% coal, 27% Nat Gas, less than 1% oil, and then the rest is clean. So, only around 40% is REALLY clean.

A BEV charged at night has NO net CO2 emissions

[evenbetternb5214]

When you charge a BEV at night, you are using power that would otherwise be wasted, because steam turbines, such as those used by Coal and Nuclear power plants, cannot be shut down fully at night, when the power load decreases. Enough power is generated and wasted every night to charge up 100 million BEVs. Those tons of Coal will be burned even if nobody is using the power, so charging a BEV at night is causing no net increase in CO2 emissions. This is the reason why electricity is so cheap late at night - it is surplus power.

I have driven a LEAF to work for over two years, and I work 30 miles from home. The LEAF already has enough range for 90% of commuters to get to work every day. In a couple years, that percentage will increase as lower-priced higher-range BEVs become available (200 mile range is a common target). Even if you don't believe that CO2 emissions are a problem, you can save a significant amount of money by driving a BEV, even when compared to driving a 50MPG hybrid. BEVs are practical for many commuters right now.

Re:I see theyre using the Step 2 profit model

[Mr D from 63]

The study is not a cost comparison. The study is not even an energy use comparison. The study is a pollution comparison.

Once again, they also do no include the sourcing and transportation contributions of coal either. And they are very transparent regarding what is included.

They also don't include the impacts from lithium extraction and distribution for batteries. Nor the impacts of battery replacement/recycling.

Solar rocks

[fyngyrz]

The sun is always shining. What you mean to say is that the sun is not always visible due to clouds or fog, or on the side of the planet that would be optimum for power generation when the sky is clear. I'm not just being pedantic. Because:

Although that is all factual, the idea that solar does not generate power when when not in direct sunlight (cloudy, foggy, shaded, etc.) is wholly incorrect.

Solar works all day, every day, no exceptions. Rather than "not work", it varies in efficiency, and not so much that it doesn't remain useful when it is cloudy; efficiency of a well aimed system on cloudy days varies from about 20% to 50%, depending on the tech in the panel and just how dense the occlusion is. Here's a back-yard demonstration of exactly that. (TL;DW -- he gets about .6 amps out of his 4-amp panel on a cloudy day, without aiming: about 15 % efficiency.)

The more exposure and better angle you have, of course, the better it all works. But clouds and fog... facts of life. Yet you can still get all the energy you need from a solar system on days that aren't perfectly clear. You can even plan for it, and build in enough overcapacity (with full sunlight in mind) so that you always have enough power.

Concrete example: I have a small trailer that I have some 12 vdc ham gear in. It has lights, a refrigerator, and a 100-watt HF transmitter that pulls about 200 watts, worst-case. On the 10x6 roof, I have 6, (nominally) 100 watt solar panels. Minimum I've *ever* seen out of them at midday, on a cloudy winter day, is about 6 amperes. That's about 90 watts of continuous charge. I never, ever run out of power. Sunny days I have ridiculous amounts of excess power available, and I run an air conditioner or a heater with it.

I have an (unfortunately large, this tech isn't really where it needs to be yet) bank of ultracaps in the trailer. No batteries. I also run LED lighting and a very efficient small refrigerator. Surge power to start the compressor is no problem - the ultracaps can deliver far more than is required. Once running, the fridge's power draw is negligible. The charge and supply electronics are of my own design (ultracap discharge slopes aren't like batteries, so you need something significantly more complex than a wire and a fuse) and no doubt they could be improved, but I have never run out of power and I transmit quite a bit at times.

I've also gone out at night and done many hours of shortwave dx'ing (in the country, away from the town's copious RFI), lights on, opening the frig once about every half hour, and not run out of power.

My home's main roof area is 60x45. That's room for about 360, 100-watt panels, or about 36,000 watts of peak capacity. At 80% derating -- what we can anticipate on a really, really overcast day -- peak output is still about 7,000 watts. Quite usable for lighting and light duty loads. the pacemaker will get charged. :)

My house is very well insulated, too, so that's a bonus, heating- and cooling-wise.

Solar is the way to go. Period. All those rooftops, all those square miles of empty space, just waiting for us to get in gear.

Currently, individual ready-to-mount 100-watt solar panels are about $135 on Ebay, with a 25-year warranty. less in quantity. The math is quite compelling, even with the major shortcomings of battery lifetime. Set up a small system to run something. Learn the basics and work through it so you understand it. Batteries, charge controllers, panels, aiming and auto-aiming and either low voltage client devices like my trailer system, or an inverter and the usual type of 120 vac power clients. If you do, I suspect your enthusiasm level will change dramatically for the positive. There's something ultimately satisfying about spending money on YOUR infrastructure and giving the bird, even if it's a very small bird, to the power company.

Re: I see theyre using the Step 2 profit model

[tbannist]

It also has tons of advantages Which is why in any country that isn't taxed the hell out of, it's the preferred power source.

It has one advantage, it's cheap, and it's the preferred power source when coal isn't taxed (or more commonly where it's actually subsidized), because it's cheap. Additionaly, since most of the disadvantages are either invisible (for example, cancers caused by radioactive coal soot) or are somebody else's problem (like coal sludge dumped in someone else's water supply), those costs are not factored into the average user's decisions.