LIFECYCLE CO2eq OF INTERNAL COMBUSTION VERSUS ELECTRIC VEHICLES

Almost all studies compare ICs and EVs, as if they traveled the same number of miles over a period of years. This is a serious error, because EVs travel, on average, about 9642 miles per year and ICs about 13433 miles per year, i.e., EVs travel about 28% less miles than ICs. The average annual miles driven by a driver is 13476. See Appendix.

In actual practice, EVs are mostly used for shorter trips, because of a lack of range, but ICs are used for short and long trips. That means a second vehicle, which may be owned, leased, rented or borrowed, is required for 13433 - 9642 = 3791 miles per year.

 

Almost all studies also do not account for:

 

- The increased internal resistance of the battery, which means more electricity/mile is required as the battery ages.

- The energy expended for extraction, processing, and transportation of fuel for ICs, i.e., from well to tank,

- The energy expended for extraction, processing, conversion and transmission of electricity for EVs, i.e., from mine, well, etc., to house meter

- The embedded energy, and resultant CO2 emissions, of the vehicles. 

 

This comparison accounts for all of the above 5 items, which significantly reduces the CO2 emissions advantage of an efficient EV over an efficient IC.

EV and Hybrid Sales in 2018 

Every month InsideEVs tracks all the plug-in EV and hybrid sales/deliveries for the US by automaker and brand. This partial list shows the best sellers at the top are EVs with big batteries and long ranges. That means upscale households who can afford these vehicles want a driving range of at least 250 miles. The Tesla Model 3 numbers likely will increase by about 150,000 by the end of 2018, due to a production increase.

https://insideevs.com/monthly-plug-in-sales-scorecard/

 

2018 EV and Hybrid Sales	Type	Jan	Feb	Mar	Apr	May	Jun	YTD
Tesla Model 3	EV	1875	2485	3820	3875	6250	6062	24367
Toyota Prius Prime	Hybrid	1496	2050	2922	2626	2924	2237	14255
Tesla Model S	EV	800	1125	3375	1250	1520	2750	10820
Tesla Model X	EV	700	975	2825	1025	1450	2550	9525
Chevrolet Bolt EV	EV	1177	1424	1774	1275	1125	1083	7858
Chevrolet Volt	Hybrid	713	983	1782	1325	1675	1336	7814
Nissan LEAF	EV	150	895	1500	1171	1576	1367	6659
Honda Clarity PHEV	Hybrid	594	881	1061	1049	1639		5224
Ford Fusion Energi	EV	640	794	782	742	740	604	4302
BMW i3 (BEV + REx)	EV+Hybrid	382	623	992	503	424	580	3504
Chrysler Pacifica Hybrid	Hybrid	375	450	480	425	650	710	3090
BMW 530e	EV	224	413	689	518	729		2573
BMWX5 xDrive 40e	EV	261	596	627	563	499		2546

Basis of Comparison

 

I assumed a household has an EV as the primary vehicle and an IC as the secondary vehicle. For performing the required short and long trips, an efficient EV/IC combo should be compared with an efficient IC. See spreadsheet.

 

The comparison was based on the EPA Combined values for medium-size passenger vehicles:

 

- EV electricity consumption is at 31 kWh/100 miles, or 100 x 33.7/31 = 108.7 mpg equivalent, on a year-round basis in year 1.

- IC fuel consumption is at 30 mpg of gasohol (90 gas/10 ethanol) on a year-round basis.

 

NOTE:

 

- EPA assumes 33.7 kWh is equivalent to one gallon of gasoline, or 115,000 Btu. It takes about 115000/0.35 = 328571 Btu of source energy (well, mine, etc.), which if converted to primary energy to power plants, would produce 33.7 kWh at the house meter.

 

Efficiency of US power system	0.35
		Btu	kWh
Inputs, various forms of energy, 1.0/Efficiency	2.857	328571
Losses, conversion, transmissions, etc.	1.857	213571
Output	1.000	115000	33.7

Ethanol Production: It takes about 817,113 Btu of various energy inputs to produce 1 million Btu of ethanol, well-to-pump basis; energy multiplier = (1000000 + 97301, co-products credit)/817113 = 1.34. See page 4 of URL.

https://www.arb.ca.gov/fuels/lcfs/042308lcfs_etoh.pdf

 

Gasoline Production: See below table for energy required to produce one unit of gasoline. It takes only 230,000 Btu of various energy inputs to produce 1 million Btu of gasoline, well-to-pump basis; energy multiplier = 1000000/230000 = 4.35

https://www.linkedin.com/pulse/so-exactly-how-much-electricity-does...

 

Energy for one unit of gasoline, well to pump
Extraction/recovery	0.980
Refining	0.845
Distribution/transport	0.984
Storage	0.998
Efficiency, well to pump	0.813
Inputs, various forms of energy, 1.0/Efficiency	1.230
Losses	0.230
Output, 1 unit of gasoline	1.000
Energy multiplier, 1000000/230000	4.35

NOTE: EVs are designed for minimum energy consumption to maximize range. If ICs were similarly designed, they would have much better mileage, likely in excess of 35 mpg for a medium-size passenger vehicle.

 

NOTE: If a medium-size EV/IC combo were compared with Toyota Prius hybrid (non plug-in; 54 mpg EPA combined), the EV/IC combo would have significantly more CO2 emissions (embedded + operating) than the Prius, on a lifetime basis.

Source Energy CO2 Emissions

1) The energy to EVs is on a source (mine, well, etc.)-to-electric meter basis. Many comparison studies ignore any energy before it arrives at the meter, which make EVs look much better than ICs. That is not true in the real world.

The US grid had CO2 emissions of 1.128 lb/kWh in 2016, on a source (mine, well, etc.)-to-electric meter basis. See Appendix.

 

2) The energy to ICs is on a source (mine, well, etc.)-to-tank basis.

E-10, gasohol, has CO2 emissions = 1.2568, upstream factor x (17.68, Fossil Fuel + 1.27, Ethanol) = 23.816 lb/gallon, per EIA. See URL.

http://www.patagoniaalliance.org/wp-content/uploads/2014/08/How-muc...

Battery Embedded CO2eq Emissions

The embedded CO2eq, on a source (mine, well, etc.,)-to-factory gate basis, refers to the energy uses for mining, processing and transporting, and for battery cell and battery pack manufacturing. The embedded CO2eq of a battery pack is about 43% of an entire medium-size EV. See table.

- The IC is assumed to have about 5.60 metric ton of CO2eq emissions. See URL.

- The EV/IC combo is assumed to have 14.40 metric ton of CO2eq emissions.

https://www.triplepundit.com/2011/06/full-life-cycle-assesment-elec...;

NOTE: EVs with large capacity batteries, such as the full-size Tesla Model S (75 to 100 kWh), have about 1.5 times higher battery embedded CO2eq emissions than a medium-size EV. See table.

 

	Vehicle	Battery	Total	Total
	metric ton	metric ton	metric ton	lb CO2eq
EV, medium-sized	5.00	3.80	8.80	19401
IC, medium-sized	5.60		5.60	12346
EV/IC combo, medium-sized			14.40	31747
Tesla Model S, full-sized	7.00	5.70	12.70	27999

The below spreadsheet shows:

- The miles traveled and the CO2 emissions of the EV, the IC and the EV/IC Combo.

- The battery efficiency decreasing about 7% by year 10, i.e., more kWh/mile is needed in later years. See note.

- The embedded and operating CO2 emissions of the EV/IC combo and IC.

	Travel					Travel		Travel
	72% EV					28% IC		IC
				Electr.	CO2		CO2		CO2
yr	mile/y	eff factor	kWh/mile	kWh/y	lb/y	mile/y	lb/y	mile/y	lb/y
1	9642	1.000	0.310	2989	3370	3791	3010	13433	10664
2	9642	0.992	0.312	3012	3397	3791	3010	13433	10664
3	9642	0.984	0.315	3036	3423	3791	3010	13433	10664
4	9642	0.977	0.317	3060	3451	3791	3010	13433	10664
5	9642	0.969	0.320	3085	3478	3791	3010	13433	10664
6	9642	0.961	0.323	3110	3506	3791	3010	13433	10664
7	9642	0.953	0.325	3135	3535	3791	3010	13433	10664
8	9642	0.946	0.328	3161	3564	3791	3010	13433	10664
9	9642	0.938	0.331	3187	3594	3791	3010	13433	10664
10	9642	0.930	0.333	3214	3624	3791	3010	13433	10664
	96420			30991	34942		30096	134330	106642
								EV/IC	IC
								CO2eq	CO2eq
								lb	lb
							EV electr.	34942
							IC fuel	30096	106642
							Embedded	31747	12346
							Lifecycle	96785	118988
							Metric ton	44.9	54.0
									23%

Less Range and More kWh/mile After Aging

Based on owner-reported driving results, Tesla Model S batteries retained 95.6% of their original range after 50,000 kilometers (31,068 miles, or 31068/13433 = 2.3 years), and 94% at 100,000 km (62,137 miles, or 4.6 y), and remained above 90% as far out as 250,000 km (155,352 miles, or 11.6 y).

 

These reported results were based on the vehicle meter, which measures the kWh already in the battery (state of charge); losses from house meter, AC to DC conversion, and charging into the battery are ignored. Table 2 does NOT ignore those losses.

https://qz.com/1325206/tesla-owners-battery-data-show-it-wont-win-t...

 

NOTE: See figure 7 in URL, which shows increased internal resistance and loss of capacity for only 40000 h, or 4.56 y

https://www.sciencedirect.com/science/article/pii/S030626191731190X

 

NOTE: The average age of US light vehicle population was about 11.6 years in 2016. In this comparison, the EV life was taken at 10 years, because of increased sluggishness and lesser range in later years, which would be especially noticeable driving uphill, on dirt roads, with snow and ice on roads, and during cold weather when heating of the battery and the passenger compartment is required. See Appendix.

http://www.autonews.com/article/20161122/RETAIL05/161129973/average...

 

Table 1/Age	New	10y	11y - 15y
Charging
House meter to battery	0.978	0.978	0.978
Battery internal resistance	0.965	0.876	0.862
Phantom loss	0.887	0.887	0.887
Loss factor	0.837	0.760	0.748
Loss, %	16.3	24.0	25.2
Discharging
Battery internal resistance	0.965	0.876	0.862
Battery to wheels	0.970	0.970	0.970
Loss factor	0.936	0.850	0.836
Loss, %	6.4	15.0	16.4
Range, miles	300.0	272.3	268.0
Remaining range, %		90.8	89.3
Loss factor, house meter to wheels	0.784	0.646	0.625
Loss, house meter to wheels, %	21.6	35.4	37.5

Conclusion

 

As the future US grid becomes cleaner, the 23% EV/IC combo advantage over ICs would increase. To make the US grid cleaner with less coal, and more natural gas, and more renewables, such as wind, solar, etc., is very expensive, especially, if nuclear, coal, gas and oil plants are shut down and replaced with massive build-outs of 1) wind and solar, and 2) very large capacity energy storage systems, and 3) expanded grid systems. See URLs.

 

As future ICs likely would get better mileage, the 23% EV/IC combo advantage over ICs would decrease. To make ICs more efficient is not very expensive, as proven by the Toyota Prius hybrid, and the Toyota Prius hybrid plug-in (which has a slightly larger battery), both of which are rated at about 54 mpg EPA combined.

More Hybrids Much Better Than More EVs

A much larger build-out of plug-in hybrids, instead of EVs, would:

 

- Require far fewer public charging stations (nearly all of the hybrids would charge their smaller capacity batteries at home). Non plug-in hybrids, such as the Toyota Prius (54 mpg EPA combined), do not require charging stations.

- Require minimal or no subsidies.

- Impose a much lesser burden on the US electricity supply system.

- Eliminate range anxiety.

- Greatly reduce the battery disposal/recycling problem.

 

http://www.windtaskforce.org/profiles/blogs/wind-and-solar-hype-ver...

http://www.windtaskforce.org/profiles/blogs/a-likely-scenario-durin...

http://www.windtaskforce.org/profiles/blogs/new-england-will-need-t...

http://www.windtaskforce.org/profiles/blogs/daily-shifting-of-wind-...

 

APPENDIX 1

Source to Meter: Electrical energy has a source energy, which, if reduced by about 8% due to exploration, extraction, processing and transport, becomes the primary energy fed to power plants, which convert that energy into electricity, which after transmission and distribution losses of about 6.5%, arrives at user meters. As a result, the energy fed to the meter has to be multiplied by 2.8776 to obtain source energy. The source CO2 of the US grid was 1.2712 lb. of CO2/kWh in 2013 (1.1275 in 2016). See Table 8, Appendix 2.

 

Source to Tank: E10 fuel (90% gasoline/10% ethanol) has a source energy, which, if reduced due to exploration, extraction, processing and transport, becomes the primary energy fed to E10 vehicles. As a result, the energy fed to the tank has to be multiplied by 1.2568 to obtain source energy. The source CO2 of E10 is 1.2568 x (17.68, Fossil Fuel + 1.27, Ethanol) = 23.816 lb. CO2/gal, per EIA. See URLs.

 

http://www.patagoniaalliance.org/wp-content/uploads/2014/08/How-muc...

http://www.windtaskforce.org/profiles/blogs/source-energy-and-prima...

APPENDIX 2

US CO2 Emissions Decreased Due to Less Coal and More Natural Gas: The URL shows the unusually rapid decrease of CO2 emissions during 2015 and 2016. Such a rapid decrease likely will not occur during the next few years, as natural gas prices likely will increase due to exports, and as changes in EPA rules likely will cause fewer coal plants to close. A “cleaner” US grid would mean EVs would compare more favorable with E10 vehicles regarding emissions.

https://www.eia.gov/totalenergy/data/monthly/pdf/mer.pdf

 

Table 8
Year	2013	2016
CO2, MMt	2053	1821
To meters, TWh	3845.38	3845.38
kg CO2/kWh	0.5339	0.4736
lb/kg	2.2046	2.2046
lb CO2/kWh, PE basis	1.1770	1.0440
Upstream factor	1.08	1.08
lb CO2/kWh, SE basis	1.2712	1.1275
g/lb	454	454
g CO2/kWh, SE basis	577	512

APPENDIX 3

Plug-in Driving in New England

 

With snow and ice, and hills, and dirt roads, and mud season, 4-wheel/all-wheel drive vehicles, such as SUVs, ¼-ton pick-ups, minivans, are a necessity in rural areas.

 

Here is a list of plug-ins. Very few have 4-wheel/all-wheel drive and some of them cost 1.5 to 3 times as much as a Subaru Outback, which has all-wheel drive.

http://www.plugincars.com/cars

 

Plug-in EV: Driving an EV in winter, with snow and ice, and hills, and dirt roads, and mud season, and at low temperature, say - 10 C, with the heat pumps heating the battery and the passenger cabin, would be very sluggish going, unless the EV had a large capacity, kWh, battery. The additional stress would cause increased battery aging and capacity loss.

 

There are EVs, such as the Tesla Model S, $80,000-$100,000, with 75 - 100 kWh batteries, which offer road-clearance adjustment and all-wheel drive as options, but they are out of reach of almost all Vermonters.

 

Plug-in Hybrid: Driving a plug-in hybrid in winter, such as a Toyota Prius Prime, 54 mpg, would be much better, but it does not have 4-wheel/all-wheel drive, a major drawback; the major reason I drive a Subaru Outback.

http://www.windtaskforce.org/profiles/blogs/evs-and-plug-in-hybrids...

APPENDIX 4

Vermont: 

Plug-ins increased from 88 in July 2012 to 1522 in January 2016. 

Pure EVs totaled 330, about 330/1522 = 22% of all plug-ins.  

The plug-in increase was about 1522 - 1113 = 409 from Jan. 2015 to Jan. 2016.

Total plug-ins could be as much as 2000 at end 2017 

New vehicle registrations were 41000 in 2016. 

Plug-in registration was about 409/41000 = 1.0% of all new vehicle registrations. 

The VT Comprehensive Energy Plan goal is 4700 new plug-in registrations in 2025. See page 164 of CEP. It is likely about 78% of the plug-ins would be hybrids.

People favor hybrids over EVs, because EVs just do not have the range and are terrible performers under Vermont winter conditions. See below.

APPENDIX 5

The annual average miles a vehicle is driven is shown in the table. The average annual miles driven by a driver is 13,476. That means quite a few cars are underused, i.e., many people have two cars, but mostly use one of them.

 

https://www.afdc.energy.gov/data/10309

https://www.fhwa.dot.gov/ohim/onh00/bar8.htm

 

IC Vehicle type	Annual miles
Light truck	11,712
Light-Duty Vehicle	11,346
Car	11,244

 

Annual miles of EVs and Hybrids Much Less Than IC Vehicles: The below table shows the average annual miles travelled by EVs is 9642, about 28% less than the 13433 of ICs. This is likely due to EVs being mostly used for local trips (because of a lack of range) and ICs being used for local and longer trips. See table.

 

Plug-in Hybrids, with Large Capacity Batteries: The Chevy-Volt has a large capacity battery and travels, on average, about 74% of its annual miles in electric mode. See table.

 

Plug-in Hybrids, with Small Capacity Batteries: The Honda Accord and Toyota Prius PHEVs have small capacity batteries and travel 22% or less of their annual miles in electric mode. See table

https://insideevs.com/annual-electric-miles-traveled-varies-widely-...

 

Type	Electric	PHEV	Total	Battery %
Nissan Leaf	9697		9697	100
Ford Focus Electric	9548		9548	100
Honda Fit EV	9680		9680	100
PEV average			9642
ChevyVolt	9112	3126	12238	74
Ford C-Max Energi	4069	8334	12403	33
Ford Fusion Energi	4337	8066	12403	35
Honda Accord	3336	11650	14986	22
Toyota Prius	2484	12652	15136	16
PHEV average			13433
PHEV/PEV, %			28

APPENDIX 6

One Year of REAL WORLD Experience With a Tesla Model S: An upstate New York owner of a Tesla Model S measured the house meter kWh, vehicle meter kWh, and miles for one year (bold numbers in table). There was significant kWh/mile variation throughout the year. His real world annual average was 0.392 kWh/mile, house meter-to-wheel. The Model S has regenerative braking as a standard feature. The owner did not take into account the source-to-house meter electricity losses.

 

- Owners may use 0.392 kWh/mile, or less, in other US regions.

- New EVs would use less kWh/mile than older EVs, due to battery system degradation.

- Data, as measured by owner in New York State, covers only the driving energy. The embedded CO2 is ignored.

 

See URLs, especially the second, which has a wealth of data.

 

http://www.greencarreports.com/news/1090685_life-with-tesla-model-s...

http://www.uniteconomics.com/files/Tesla_Motors_Is_the_Model_S_Gree...

 

Tesla, Model S		EV	IC
Electricity cost, c/kWh	14
Mileage, miles/gal			30
Fuel, E-10, $/gal			2.80
Miles in one year	15243
kWh, vehicle meter, kWh in one year	5074
kWh/mile, vehicle meter basis	0.333	5074/15243
kWh/mile, vehicle meter basis	0.301	Apr-Oct
kWh/mile, vehicle meter basis	0.290	July
kWh/mile, vehicle meter basis	0.371	Nov-Feb
kWh/mile, vehicle meter basis	0.400	Jan
Charging loss	626
Phantom loss; 1 kWh/d	365	c/mile	c/mile
kWh, house meter	6065	5.48	9.33
kWh/mile, house meter basis	0.398
Loss, house meter  to battery	16.3%	100 x (1-0.333/0.398)

 

APPENDIX 7

Thanks to Akilae from the Model 3 Owners Club, we can now compare the efficiency between the three Tesla models currently on sale.

https://pushevs.com/2017/08/01/tesla-model-3-efficiency-impressive/

 

Below are the internal efficiency numbers that Tesla uses to rate its electric cars:

 

Tesla Model 3: 23.7 kWh/100 miles – 14.73 kWh/100 km

Tesla Model S: 34.4 kWh/100 miles – 21.38 kWh/100 km

Tesla Model X: 36.9 kWh/100 miles – 22.93 kWh/100 km

 

Tesla and EPA figures aren’t exactly the same, so for of comparison here are some EPA combined efficiency numbers:

Tesla Model S 75D: 33 kWh/100 miles – 20.5 kWh/100 km

Hyundai IONIQ Electric: 25 kWh/100 miles – 15.4 kWh/100 km

APPENDIX 8

Below is a summary of US corn production for ethanol for 2016/2017. A very efficient, medium-size car, 28 mpg, would use about 478 gal of pure ethanol (75583 Btu/gal LHV) to travel 13394 miles; one acre per car.

 

NOTE:28 mpg on propane is equivalent to 115000/75583 x 28 = 42.6 mpg on gasoline.

 

- The US does not have significant additional acreage for corn production.

- The US had about 269 million motor vehicles in 2016, including about 113 million registered automobiles.

- At present, almost all 113 million automobiles use gasohol (90% gasoline/10% ethanol). If gasohol were 85% gasoline/15% ethanol, as advocated by ethanol promoters, at least 40 million additional acres would be required.

- The embedded energy for the entire infrastructure to produce corn and ethanol, and its continued renewal, requires billions of dollars of investments each year.

- Much more efficient biofuels production processes need to be invented, because ethanol from corn, which requires significant fossil fuel inputs for cropping and processing, could never displace more than 75583/115000 x 10 = 6.57% of gasoline used in passenger vehicles.

- It would be much easier, and much less costly, to increase the mileage of the 115 million passenger vehicles, than have the politics-inspired, subsidized, environmentally destructive, marginally effective, corn to ethanol program.

 

https://www.agmrc.org/renewable-energy/renewable-energy-climate-cha...

https://www.engineeringtoolbox.com/fuels-higher-calorific-values-d_...

https://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf

http://acmg.seas.harvard.edu/people/faculty/mbm/Ethanol_chapter1.pdf

http://www.cleanfuelsdc.org/pubs/documents/EnergyBalanceIssueBriefM...

http://www.americanenergyindependence.com/ethanol.aspx

http://www.theoildrum.com/node/1724

 

Corn	2016/2017
Planted, million acre	85.8
Crop + in stock, billion bushel	16.178
In stock, billion bushel	1.708
Crop, billion bushel	14.470
Bushel acre	169
Planted for ethanol, million acre	31.4
Corn for ethanol, billion bushel	5.30
Ethanol production, million barrels/d	0.98
Gal/barrel	42
Ethanol production, billion gal	15.02
Gal/acre/y	478
Wet and dry mill average, gal/bushel	2.83
Ethanol used for fuel, billion gal	14.80
Gasoline, billion gal	133.20
Gasohol, if all 90/10, billion gal	148.00
Ethanol, Btu/gal, LLV	75583
Mileage using 100% ethanol, miles/gal	28
Miles/acre/y	13385
Acres/car using 100% ethanol	1.0