A long paper describing how the Model S is not green.
http://www.uniteconomics.com/files/Tesla_Motors_Is_the_Model_S_Green.pdf Someone spent a lot of time combing through the forums here, linking member's posts. I have not yet gone through it all, but I really wish Tesla would kill that damn vampire load already.
The united economics paper is garbage
After dissecting this piece of propoganda I found many, many inconsistancies with the paper.
First, they assumed the worst of the worst for the CO2 emissions for both coal and natural gas. That 1021 looks remarkably like the CO2 emissions from a coal plant WITHOUT scrubbing or carbon capture techniques. Coal with scrubbing emits 960 g CO2 per kwrh. Clean coal emits between 98-396 g CO2 per kwhr. Remarkably below the 1021 cited, which is from a 2006 EPA website.
What about natural gas? Well, they cited 517 g/kwhr. Again this number is very, very high. Natural gas is typical around 450, but if you have carbon capture techniques it is between 65-245 g CO2 per kwhr
Where did I get my data from?
http://srren.ipcc-wg3.de/report/IPCC_SRREN_Annex_II.pdf
http://www.nirs.org/climate/background/sovacool_nuclear_ghg.pdf
http://www.oxfordresearchgroup.org.uk/sites/default/files/secureenergy.pdf
These are newer than the 2006 data used for their analysis. So If you plug in the 450 and the 960, you get 495 grams/kwhr. Right now they are off by 16% and we are still on page 2 of the study.
Now, let's look at the Model S driving efficiency. Yes, 300 miles per charge is possible, but as per the EPA it's really 265 miles per charge, or 0.32 kw per mile. So let's we what we are up to in terms of grams CO2.
0.32 kwhr/mile * 495 gram CO2/ kwhr = 159 grams CO2 per mile. Lower than what the article suggests.
Now, we are also assuming that the EV driver is purely using the average grid to power his car. This is not really the case and there's a lot of assumptions that have to be made to assume this is the case. Here's the assumptions
1.They are trickle charging to get the grid average
2.The EV owner does not own a house and using other charging solutions
3.The EV owner does not have solar
4.The EV owner has no future plans to get solar
5.If the EV owner does have solar they are not utilizing it to power the car
6.The EV owner is not charging at night
7.The EV owner never plans on using the Tesla supercharger network
Well, lets look at each of these assumptions and see if they are reasonable.
Assumption 1, it's pretty unreasonable to assume a person, specifically in a Tesla Model S is going to let it charge for 24 hours, drive it for a week and then let it sit for 24 hours to charge. That's an unreasonable assumption
Assumption 2, well, if you purchase a $100,000 car and are renting an apartment or a house, I think it's time to reevaluate your monetary habits.
Assumption 3,4, and 5. Yes, that's possible, but keep in mind the target audience for the car; environmentally minded individuals. The individuals who purchase an EV probably are more likely to have solar than a random individual. They are also more apt to install more solar cells in order to power their car.
Assumption 6: This is a shaky one, because during the night, the loads are kicked back due to non-use to a certain baseload. There's a few ways to look at these either a new EV plugged in at night becomes part of the nighttime base load OR it becomes a new load powered most likely by a natural gas peaker or wind. At least in my region, its about a 75 nuclear/ 25 coal split at night, so if you consider it a base load, it's roughly 77 grams CO2 per mile. If it's natural gas powered it's 144 grams CO2 per mile. But let's go into the peak vs non-peak, yes, you have demand, but if you add a new supply, let's say nighttime wind, does that count as base. Most people would say that that is new base load so that would lower the emissions per night, now you can't have it both ways, new supply counted as base, but new demand counted as peak.
Assumption 7: This may or may not be the case, but remember the supercharger network is grid tied so it is making the grid cleaner.
Now we get to the complaint about the 265 being now accurate. Keep in mind that was done as per the EPA test, not highway speeds as was also stated in the motortrend article. They also failed to mention that Musk's perosnal car has the 21 inch rims, which does effect the range. Using the 21 inch rims decreases the range by about 6%. Tesla also stated that. Also they pointed out that it's 0,424 kwh per mile, and Musk was loaning his car out to people? Every Tesla owner will tell you for the first few hundred miles they had substantially higher energy usage. 0.42 seems about right for the first few hundred or so of my miles. Different driving techniques and learning how to drive it without accelerating like a rocket?
Citing some owners, specifically in winter conditions and calling it good data is not exactly that accurate to say the least. You don't know exactly what their conditions are, their driving habits or what else they are doing. I'm sure all the 85 kwhr Model S owners are keeping the speed limit, letting trucks pass them, and driving mimicking the EPA test EXACTLY. I had a Mercury that got 22 mpg when it was rated for 24, I also had a car that got 8 mpg when it was rated for 19. Heck, look at the Fusion and Cmax, they are getting 20% LOWER mpg than advertised as per fuely.com.
Ford C-Max MPG Reports | Fuelly
or how about the Prius- that's 48-50 and people are getting 46.4, or 5% off.
2013 Toyota Prius MPG Reports | Fuelly
Now they cite the model S, getting 0.37 instead of 0.32, that's 16% off. By the way did I mention these numbers were reported during WINTER driving and the heater and heated seat combination consumes roughly 3 kwhr, at least that's what I have documented.
With regards to the power input and battery charging losses, it depends on the type of charger used. If a 120 V is used the battery losses should be larger. I can speak from my own experience in that it takes 90 kwhr to charge 85 kwhr, but again, it depends on the type of outlet used and vampire drain from other applications (i.e. having the 120 V has to account for vampire drain and internal resistance more than the 220 or 480 V charging).
Also, they got the type of batteries wrong, the type of batteries used in the Model S are NCA, not lithium cobalt, iron phosphate or managnese oxide.
Yes, there will be some loss due to running the software, but after a while the model S goes into standby model in which the energy consumption drastically decreases, this is different than the sleep mode. Sleep mode which was disabled in version 4.2 of the software. Sleep mode would allow the Model S to conserve power and it did that, as it was designed, but other functionality was compromised so they removed it and plan to put it back.
Now the infamous Broder article. Any person that cites a journalist who exaggerated needs to question their entire book of work and their sources. The editor more or less printed an apology and side 75%-90% with Tesla. It's pretty hard when your boss publicly sides with someone else. Yes, there was an algorithm issue, it was not range loss as pointed out due to cold, but an algorithm issue in the display due to the cold. I've had this happen to myself, went to work with 170 miles on the display, came out 9 hrs later and it said less, BUT it was a phantom reading, I made it almost the entire way home without the rated mileage going down significantly.
We get into the pseudo electric bill evidence. Well bill statements are not exactly 100% correct, its very difficult to use billing statements except as a ballpark. Yes, some went up as expected, some went down lower. I question if the behavior was the same. Maybe the owner decided to watch the Hobbit on his plasma TV, or did 2 extra loads of laundry, or used a microwave more often, maybe took an extra long shower, or did something different, those are possibilities which could explain why the energy is close. It's extremely hard to say unless you actually measured the energy usage for the entire month, I'm not saying the BULK is not attributed to the Model S, but you really can't pinpoint. As cited from the references in the article, some went up significantly, some were less than the theoretical. As an example the user Teslaguy, as cited in the article, used 8% LESS energy than expected.
For example, I drive put on about 1,000 miles per month with my Model S. My last electricity bill the year to year difference was about 300 kwhr. That doesn't make sense, that means I was putting 0.3 kwhr per mile, I know for a fact I was putting more energy in than that... Oh wait, a year ago I was watching more TV and doing other energy draining stuff. Like I said, energy usage is not a highly controlled measurement and can only be used as a ballpark.
Next, the 630 miles per month. Bad science, bad research, skewing the results right there, AND contradicting their own research stated earlier (Meduri 2500 miles in a month anyone??). You have to assume it's an average car in terms of driving, assuming it's a 1%er collector car driven only on nice days calls into question the bias of the article. So there's another hole in the paper right there.
The we get to the shaky fuel efficiency numbers. Well it's a large luxury sedan, not an econo-car, and has a different audience.
Now let's look at some of it's competitors, Porsche Panamera, BMW 7 series, and the Mercedes, their competitors are getting roughly 19-21 mpg. Why use a $15,000 Civic to skew the results, unless it's an exercise in propoganda. If we feel compelled to compare a Civic to a Tesla, let's compare a Subaru 360 to a Civic, I mean, the percentage horsepower difference is the same, the cost difference is roughly the same, AND the weight difference is the same and the step difference for the cars are the same (large car vs a small car, then a small car vs a micro car). If you do that, the Civic looks really, really bad compared to a Subaru 360.
Also the energy cost is bogus also. As cited earlier, it is entirely possible to have solar and have scaled the system specifically for the EV. It is also possible that they went with other, cheaper electrical providers. While they acknowledge that the time of use could be made independently and switching other providers could have been made independently, with regards to the time of use, it does not make sense to switch unless you are consuming energy at night, during off peak hours. Yes, they could have switched electrical providers too, but again, a significant increase in electricity would be a driver to switch to cheaper electricity.
Wait.. there's more cherry picking in energy cost! Now they assumed not using time of use AND in California, probably the worst case scenario, then they go on to use the mpg of a Civic with the national gas average. I guess they failed to realize gas prices in California are higher too!
Ok, then you get to their environmental analysis and their sources:
Lomborg, really? As many of you may be aware he was brought up on scientific dishonesty charges when he wrote his first book. That's pretty bad. But let's look at his environmental credentials and education. Yes, a political scientist has as much training and an environmental scientist in terms of engineering and life cycle assessments. That's like saying a lawyer has as much training as a chemist in chemistry. Very foolish to place faith in such a character.
The Hawkins paper, again, that was a horrible, horrible LCA. Where do I start? Well, they failed to use a reasonable vehicle life, used lower density batteries, and used batteries which no EV in the US uses. As you may or may not be aware, LCA are VERY, VERY sensitive to input materials. Using Iron phosphate or NCM instead of NCA has HUGE impacts. They also fail to consider recycling. More or less, this was a garbage LCA. The infamous Norway study was also cited, again, garbage in garbage out. Yes, let's again cherry pick the worst of the worst that have thoroughly debunked and use them to make out point.
They also contradicted themselves, again with the mileage, assuming 8,000 miles per year. Interesting that some users as cited earlier put on as many as 2500 miles in a month, others 1250, and myself 1000. Well, their entire strategy falls apart when you start upping the mileage. Using Battery university data, yes, that's good enough. Had they actually looked at the real data and understood how battery degradation works, it appears the batteries in the Tesla S are good for 2000 cycles at 100% depth of discharge to reach 70% capacity. For those knowledgeable individuals, a partial discharge does not do as much damage to a battery as a full discharge, look up any lithium battery DoD/cycle life curve for the results.
Now their conclusions
First, they got the energy usage wrong, then they got the emissions wrong, then they over estimated the emissions. Let us use the real, actual numbers and see what we get and assume a grid average
495 g CO2 * (0.32/.9)/.93 + 3 kwhr/40= 190 grams per mile
That's roughly half of their number- I think we can clearly see there is an issue with their paper for many, many reasons and it gets compounded in their conclusions.
My brain hurts after looking at this paper for far too long
