Stoaty said:
planet4ever said:
- The carbon footprint to build an EV is unlikely to be twice that of an ICE, but let's assume that as a worst case.
Hold on there. Let's use some data from the UCLA study:
http://www.environment.ucla.edu/media_IOE/files/BatteryElectricVehicleLCA2012-rh-ptd.pdf" onclick="window.open(this.href);return false;
1) Carbon footprint to build an EV is about 5 times that to build an ICE (see attached graph, take sum of blue plus red portion of bars)
I have been researching the issue of carbon footprint of EV manufacture vs ICE manufacture. I agree it is an important issue separate from the driving (fuel) footprints. I have seen the above graph, and I am not convinced it can be relied upon. It shows a high cost for battery vs ICE engine. I am still collecting information, but it appears to me that
the negligible amount for engine of CV in this graph is not credible.
Below I offer some quotes that at least partially refute these claims.
I believe different assumptions about sources of material may be some of the cause of different estimates of manufacture. For example, Aluminum requires 12-13 kWh/kg electricity to produce(see Wikipedia). To save weight, the LEAF has aluminum door panels and the Tesla body is mostly Aluminum. However, quite a bit of global Aluminum production is now done in Iceland, using geothermal power, and Norway, using hydroelectric power. Both of these sources have zero carbon footprint, except for shipping. If the aluminum comes from China, coal was probably used to produce the electricity, with a much higher footprint.
If the steel in either an EV or an ICE is produced from iron reduced from coke, which is a type of coal, that has a substantial carbon footprint.
With respect to the battery and Lithium, here are some references from a story written by Bjorn Lomborg (BL) of the WSJ that might have been the source of your friends' negative opinions.
http://www.plugincars.com/electric-...ncludes-wall-street-journal-op-ed-126685.html
In the above story BL writes:
When an electric car rolls off the production line, it has already been responsible for 30,000 pounds of carbon-dioxide emission. The amount for making a conventional car: 14,000 pounds.
This might be the source of the factor of 2 mentioned above, but I agree this estimate is suspect as well.
"The Energy Collective" story about the same piece:
http://theenergycollective.com/maxb...-street-journal-op-ed-needs-better-accountant
has this quote:
Most researchers agree that building electric cars today requires more energy than building gasoline vehicles, but estimates for production emissions from Argonne National Laboratory are roughly three times less than those used by Lomborg.
We know the batteries are expensive, but it is possible that much of this cost is due to the high precision of their manufacture, more than the cost, energy and otherwise, of the materials. The anode,electrolyte,separator,and cathode sandwich is only 100 microns thick, and any short through this sandwich kills the cell.
BJ also says:
The mining of lithium, for instance, is a less than green activity.
He appears to be using costs for Li mining, not brine. From "The Oil Drum, " a reliable reference I have used before:
Lithium production via the brine method is much less expensive than mining, says John McNulty, analyst at global bank Credit Suisse. Lithium from minerals or ores costs about $4,200-4,500/tonne (€2,800-3,000/tonne) to produce, while brine-based lithium costs around $1,500-2,300/tonne to produce.
>>>
Chile provides 61% of lithium exports to the US, . . .
As was reported in a post above, the Chile production sounds very "green":
Melting snow from the Andes Mountains runs about 130 feet (39.6 meters) underground, into lithium deposits, then gathering into pools of salt water, or brine. The brine is pumped out from under salt flats such as Chile's Salar de Atacama, and spread among networks of ponds where the desert sun and high altitude provide a beneficial environment for evaporation.
Eventually Global Warming will eliminate the snow, and then there may be a problem in Chile.
The following reference states that the focus on Li in the battery is misplaced:
Abstract
Battery-powered electric cars (BEVs) play a key role in future mobility scenarios. However, little is known about the environmental impacts of the production, use and disposal of the lithium ion (Li-ion) battery. This makes it difficult to compare the environmental impacts of BEVs with those of internal combustion engine cars (ICEVs). Consequently, a detailed lifecycle inventory of a Li-ion battery and a rough LCA of BEV based mobility were compiled. The study shows that the environmental burdens of mobility are dominated by the operation phase regardless of whether a gasoline-fueled ICEV or a European electricity fueled BEV is used. The share of the total environmental impact of E-mobility caused by the battery (measured in Ecoindicator 99 points) is 15%. The impact caused by the extraction of lithium for the components of the Li-ion battery is less than 2.3% (Ecoindicator 99 points). The major contributor to the environmental burden caused by the battery is the supply of copper and aluminum for the production of the anode and the cathode, plus the required cables or the battery management system. This study provides a sound basis for more detailed environmental assessments of battery based E-mobility.
http://pubs.acs.org/doi/abs/10.1021/es903729a
Fig 2 from above paper:
While writing this I see evnow has posted comments that support some of these statements. I agree recycling is key.
Ideally I want to get to the point where I can say with some confidence how far I must drive a Leaf (or perhaps a Tesla) before the saving in carbon footprint from driving exceed the carbon footprint penalty from manufacture, but that depends somewhat on driving style, so I am concentrating on manufacture first.
I would agree with the skeptics that there is some low mileage value below which an EV does not make sense. I have met several Leaf owners who are driving less that 4-5 K miles per year. Perhaps the lower bound is lower. They will be able to keep their cars for a long time, but they are going to lose some capacity just from their cars sitting in warm garages.