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Comparison of Energy Efficiency and CO2 of Gasoline and Electric Vehicles

Many articles have been written about the comparison of the energy efficiency of gasoline and electric vehicles. Most such articles have various flaws. This article will avoid these flaws and will show, electric vehicles are more energy efficient than gasoline vehicles, on a source energy-to-wheel basis, which is the most rational way to make the comparison. Many studies fail to use the lower heating value of the fuel, or fail to use the correct heating value of the fuel.

Many studies calculate meter-to-wheel efficiencies of electric vehicles of about 70%, which compare favorably with the tank-to-wheel efficiencies of gasoline vehicles of about 22%, i.e., EVs are 3.2 times more efficient. But that is not even close to reality.

E10 fuel (90% gasoline/10% ethanol) has a source energy, which is reduced due to exploration, extraction, processing and transport, to become the primary energy fed to E10 vehicles. As a result, the energy fed to the tank has to be multiplied by 1.2639 to obtain source energy.

Electrical energy has a source energy, which is reduced due to exploration, extraction, processing and transport, to become the primary energy fed to power plants, which convert that energy into electricity, which after various losses, arrives at user meters. As a result, the energy fed to the meter has to be multiplied by 2.8776 to obtain source energy. After these factors are applied, the EV and E10 vehicles have values as shown in the below table. The below table is based on US 2013 CO2 emissions of 2053 million metric ton to match the available 2013 electricity generation data. See Table 8.

E10 Prius
mpg 28 34 40 52
kWh/65 miles, to wheels 16.67 16.67 16.67 16.67
Btu/kW 3412 3412 3412 3412
Btu/65 miles, to wheels 56878 56878 56878 56878
miles in one hour 65 65 65 65
Btu/gal 112114 112114 112114 112114
Btu/65 miles, T-t-W 260265 214336 182185 140143
eff, T-t-W 0.219 0.265 0.312 0.406
SE factor 1.2639 1.2639 1.2639 1.2639
eff, SE basis 0.173 0.210 0.247 0.321
gal/65 miles, T-t-W 2.321 1.912 1.625 1.250
Btu/65 miles, SE basis 328948 270899 230264 177126
lb CO2/gal, SE basis 23.95 23.95 23.95 23.95
lb CO2/mile, SE basis 0.86 0.70 0.60 0.46
g CO2/km, SE basis 241 199 169 130
g CO2/km, T-t-W 191 157 134 103
L of E10/100 km, T-t-W 8.40 6.92 5.88 4.52
EV 2013
kWh/65 miles, to wheels 16.67
eff, M-t-W 0.684
kWh/65 miles, M-t-W 24.371
kWh/mile 0.375
Btu/kW 3412
Btu/65 miles, M-t-W 83155
SE factor 2.8776
Btu/65 miles, SE basis 239287
lb CO2/kWh, SE basis 1.2712
lb CO2/mile, SE basis 0.477
g CO2/km, SE basis 134
Energy efficiency, SE basis
EV better than E10, % 27.3 11.7
EV worse than E10, % 3.9 35.1
CO2, SE basis
EV better than E10, % 44.3 32.3 20.4
EV worse than E10, % 3.5

Effect of a “Cleaner” Grid in 2016: If the 2016 CO2 emissions of 1821 MMt were used, and the 2016 electricity generation data were assumed to be about the same as in 2013, then the above 1.2712 would become 1.1275 and the EV CO2 emissions would become 0.423 lb/mile (119 g/km). Only E10 vehicles with about 45 mpg (5.23 L/100 km), or better, would have less CO2 emissions than an EV with a real-world, annual average meter to wheel of 0.375 kWh/mile (0.233 kWh/km). See below table and sections and Table 9.

EV 2016
kWh/65 miles, to wheels 16.670
eff, M-t-W 0.684
kWh/65 miles, M-t-W 24.371
kWh/mile 0.375
Btu/kW 3412
Btu/65 miles, M-t-W 83155
SE factor 2.8776
Btu/65 miles, SE basis 239287
lb CO2/kWh, SE basis 1.1275
lb CO2/mile, SE basis 0.423
g CO2/km, SE basis 119
Energy efficiency, SE basis
EV better than E10, % 27.3 11.7
EV worse than E10, % 3.9 35.1
CO2, SE basis
EV better than E10, % 50.6 40.0 29.4
EV worse than E10, % 8.2

High-efficiency Vehicles More Efficient Than Electric Vehicles: The table shows high-efficiency E10 vehicles, including hybrids, such as the 52 mpg, 4.52 L/100 km Toyota Prius, have greater energy efficiency than EVs, and less CO2 emissions than EVs, on an SE basis. It would be much less costly and quicker to significantly increase the US hybrid fleet, than to build out the EV fleet, which is still in its infancy, and would require major, expensive changes to supporting infrastructures.

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. There was significant kWh/mile variation throughout the year. His annual average was 0.392 kWh/mile, M-t-W. The Model S has regenerative braking as a standard feature. The above analysis used an annual average of 0.375 kWh/mile, M-t-W, which means I used a higher EV efficiency than measured by this owner.

Data as measured by owner in New York State. See URL

Tesla, Model S
Electricity cost, c/kWh 19
Miles in one year 15243 c/mile
kWh, vehicle meter 5074 6.3
kWh/mile, vehicle basis 0.333
kWh/mile, vehicle basis 0.301 Apr-Oct
kWh/mile, vehicle basis 0.290 Jul
kWh/mile, vehicle basis 0.371 Nov-Feb
kWh/mile, vehicle basis 0.400 Jan
Vampire/charging 0.85 c/mile
kWh, house meter 5969 7.4
kWh/mile, house meter basis 0.392

http://www.greencarreports.com/news/1090685_life-with-tesla-model-s-one-year-and-15000-miles-later

Tesla Model S Driving Ranges on Non-urban Interstate Highways Under Varying Conditions

Interstate Highway speed limits; non-urban, contiguous 48 states; 12 states @ 65 mph, 20 states @ 70 mph, 14 states @ 75 mph, 1 state @ 80 mph (Texas). See: www.ghsa.org

Tesla Model S 85 kWh. Range advertised by Tesla as 300 miles at 55 mph

Sources: www.teslamotors.com and Tesla battery engineer claims.

Table 1. Ideal driving conditions: no AC, no heat, level terrain, 300 lbs aboard, windows rolled up, constant speed, no wind.

Table 2. Ideal driving conditions, but using average AC, and average heat

Table 3. Assuming additional 15% energy consumption due to non-ideal driving conditions, heavier AC and heavier heat

Table 1 65 70 75 80
Age mph mph mph mph
New 262 241 222 200
4.5 years 243 223 205 185
9.5 years 220 203 187 168
Table 2 65 70 75 80
Age mph mph mph mph
New 236 217 200 180
4.5 years 219 201 185 167
9.5 years 198 183 168 151
Table 3 65 70 75 80
Age mph mph mph mph
New 197 181 166 150
4.5 years 182 167 153 139
9.5 years 165 152 140 126

http://images.thetruthaboutcars.com/2012/08/Model-S-range-Tables.pdf

Debunking the Phony EPA Fuel Consumption Numbers – all numbers are on a source energy basis:

 

An E10 vehicle, 28 mpg, uses 2.321 gal x 112114 Btu/gal = 260265 Btu of E10 to go 65 miles in one hour (tank-to wheel basis), per Table 6, or 328948 Btu, on a SE basis.

– An EV uses 24.371 kWh x 3412 Btu/kWh = 83155 Btu to go 65 miles in one hour (meter-to-wheel basis), or 239287 Btu, on an SE basis.

The EPA mpg gasoline equivalent is based on the energy content of gasoline. The energy obtainable from burning one US gallon of gasoline is 115,000 Btu, or 33.705 kWh, or 121.3 MJ. If a different fuel, such as E10, is used, then the Btu of that fuel is used to determine EPA MPGe.

https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent

EPA EV mileage = total miles/(fuel energy/energy/gal) = 65/(83154/112114) = 87.6 MPGe. The EPA deliberately ignores the US electrical system upstream SE factor and the E10 upstream SE factor. If the US SE factor were applied, the real mileage would be 87.6/2.8776 = 30.4 mpg, similar to the 28 mpg of the E10 vehicle, as one would expect.

The car manufacturers are in on the deal, because they are allowed to take those low MPGe numbers and average them into their CAFE mpg, making it look lower than it really is to befuddle the public, which is somewhat of a sham.

The official explanation of the EPA is that people are familiar with miles/gallon, and EPA decided to call it “miles/gallon equivalent”. Engineers may not be befuddled, but Joe Blow likely is. Just ask some average people what it means. They have no idea. That means what EPA came up with was confusing.

US-DOE/Argonne National Laboratories GREET Program: ANL wrote the Greenhouse gases, Regulated Emissions, and Energy use in Transportation, GREET, computer program. The program enables comparing the well-to-wheel efficiency of gasoline and electric vehicles. If I had used the program, the inputs would have been a fuel mix to power plants for determining the CO2 of the EV, and E10 for determining the CO2 of the E10 vehicle.

https://greet.es.anl.gov

However, lacking sufficient familiarity with the GREET program, and always wanting to see equations, instead of just accepting printed results, readily available EIA data regarding CO2 emissions from the US electricity generating system, and EIA data regarding the generation of electricity, and data from various other sources, referenced in this article, were used to perform the analysis of this article.

NOTE: The article, “Is Ethanol a Cost Effective Solution to Climate Change?” shows, after a detailed analysis of the GREET computer program, the Argonne analysts relied on less-than-fully accurate international data bases, and overestimated well-to-wheel fossil fuels consumption (and associated CO2 equivalent emissions) of petroleum fuels by up to about 9%.

http://www.theenergycollective.com/jemiller_ep/172526/ethanol-cost-effective-solution-climate-change

Quick Charging of Batteries: Because low-voltage (110V+) charging of batteries takes a long time, higher voltage (220V+) charging is often used, because it reduces charging times. However, that negatively impacts:

– Overall charging efficiencies, which increases energy consumption and costs

– Battery aging, which requires earlier battery replacement, because of a loss of storage capacity, kWh, which negatively affects driving range

– Delivering energy at required rates, which negatively affects acceleration and uphill driving.

New England and EVs: With snow and ice, and hills, and dirt roads, and mud season, all-wheel drive vehicles, such as the Subaru Outback, SUVs, ¼-ton pick-ups, minivans, are a necessity in rural areas. There are a few EVs, such as the Tesla Model S, $80,000-$100,000, which offer road-clearance adjustment and all-wheel drive as options. Here is a list of EVs and Plug-in Hybrids. Very few have all-wheel drive and some of them cost 1.5 to 3 times as much as a Subaru Outback.

http://www.plugincars.com/cars

Driving an EV in winter, with 5 cm of snow, uphill, at low temperature, say – 10 C, with the heat pump heating the battery and the passenger cabin, would be slow going, unless the EV has a large capacity, kWh, battery. The additional stress causes increased battery aging and capacity loss.

Batteries likely will come down in cost, because of mass production, and weight, due to clever packaging (which would decrease rolling resistance), but the lithium-ion chemistry is pretty well maxed out, according to Musk, CEO of Tesla.

People switching from E10 vehicles to EVs likely will not happen anytime soon. There are no compelling CO2 reasons, as shown by the above table, unless the government compels people to do so, which would be a folly, as there are so many, less expensive ways, to reduce CO2. In fact, it would be best, if the government stopped interfering with the energy business.

Efficiency of US Light Duty Vehicles: LDVs are cars, SUVs, ¼-ton pick-ups, and minivans. The average efficiency of LDVs has not changed much these past 15 years. Even though new vehicle efficiency increased during the past 15 years, it caused just a very minor increase in the efficiency of all LDVs. See table. A similarly slow increase could be expected if EVs were to replace E10 vehicles.

https://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_04_23.html

However, if more LDVs were required to be hybrids (such as the Toyota Prius), which could be more rapidly implemented by manufacturers, then an efficiency increase of at least 25% could be expected during the next 15 years, etc. Toyota has a proven line-up of high-efficiency hybrids in various sizes and shapes. Other manufacturers could have the same.

LDVs 2000 2015 2000 2015 Better
mile/gal mile/gal L/100 km L/100 km %
Existing 20.00 22.00 11.76 10.69 10.0
New cars 28.50 36.40 8.25 6.46 27.7
New trucks 21.30 26.30 11.04 8.94 23.5

A Better Future Pathway: Future E10 vehicles likely would become more efficient, more quickly, and at much less cost, especially by increased use of hybrids, than:

– EVs could improve their efficiency, because lithium-ion technology is “just about maxed-out”, according to CEO Musk of Tesla. Such future EVs likely would become less costly, but not much more efficient.

– The US electrical system could reduce its CO2 intensity, kg CO2/kWh, such as with additional capacity, MW, build-outs of renewables and enlargements of the US electrical system. With higher-efficiency E10 vehicles, no such highly visible build-outs and enlargements would be needed. In fact, the capacity of the existing E10 fuel supply systems would be more than adequate for decades.

CO2 can be much less expensively reduced by:

– Making E10 vehicles more efficient

– Increased use of hybrid vehicles, such as Toyota Prius hybrids

– Increased building efficiency (having energy surplus buildings)

– Replacing existing nuclear plants with new nuclear plants, and, in New England,

– Getting more, low-cost, near-zero-CO2, hydro energy from Hydro-Quebec.

The Source-to-Wheel Efficiency of an E10 Vehicle

Per US-EPA, the energy of the gasoline is allocated, in percentages, approximately as shown in Table 1.

http://www.fueleconomy.gov/feg/atv.shtml

Table 1 Combined City Highway
% % %
Engine 68.0 73.0 65.5
Parasitic 5.0 6.0 3.5
Drive train 5.5 4.5 5.5
Wind 10.0 4.0 15.5
Rolling 6.0 4.0 7.5
Braking 5.5 8.5 2.5
Total 100.0 100.0 100.0

At a steady velocity, on a level road, and with no wind from any direction, the propelling force of the engine offsets the external resisting forces acting on the vehicle, which are wind and rolling resistance.

Wind Resistance: The wind resistance of a medium-size vehicle was calculated using 0.5*c*A*d*V^2, where; c is drag coefficient, 0.32; A is cross-sectional area of vehicle, 2.600 m2; d is air density, 1.293 kg/m3, V is velocity, 104.607 km/h. The wind resistance is 454 newton. See Table 2.

Table 2 Units Units
Drag coefficient c 0.32
Cross-section A 2.600 m2 27.986 ft2
Air density d 1.293 kg/m3 0.0807 lb/ft3
Speed V 104.607 km/h 65 mph
Wind resistance 454 N 102.063 lb force

Rolling Resistance: The rolling resistance was calculated using m*g*f*cos (a), where; m is mass, 1250 kg; g is gravity, 9.807 m/s2; f is tire deformation, 0.01 m, a = 0.5 of tire radius, 0.2032 m. The cosine (a) is about 1. The rolling resistance is 123 N. See Table 3.

Table 3 Units Units
Vehicle mass m 1250 kg 2755.75 lb
Gravity g 9.807 m/s2 32.175 ft/s2
Tire deformation f 0.010 m 0.033 ft
0.5 of tire radius a 0.203 m 0.667 ft
cosine a 1 1
Rolling resistance 123 N 27.549 lb force

Wind + Rolling Resistance: The useful power to the wheels, kW, was calculated using f, the total of wind and rolling resistance, 577 N; d, the distance travelled in one hour, 104.607 km; J = N*m, the work done, 60,331,767; t, the time 3600, seconds; W = J/s = 16759, or 16.67 kW. See Table 4.

Table 4 Units Units
Wind + Rolling f 577 N 129.612 lb force
Distance d 104.607 km 343,195 ft
Work done f*d 60,331,767 N.m = J 44,482,152 ft.lb force
Time t 3600 s 3600 s
Watt 16759 W= J/s 16759 watt
Useful power 16.67 kW 16.67 kW

The Fuel: The vehicle is assumed to use E10, a mixture of 90% gasoline and 10% ethanol. Its lower heating value is 31.25 MJ/L. In engines, the LHV must be used. See Tables 5 and 6.

Table 5 HHV HHV LHV LHV
Btu/gal MJ/L Btu/gal MJ/L
Gasoline 124340 34.65 116090 32.35
Ethanol 84530 23.56 76330 21.27
E10 120359 33.54 112114 31.25

http://www.straferight.com/forums/general-chit-chat/178951-ethanol-vs-gasoline.html

http://hydrogen.pnl.gov/tools/lower-and-higher-heating-values-fuels

https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent

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

Source-to-Wheel Efficiency: The tank-to-wheel efficiency is the useful power of Table 4 divided by the supplied power in Table 6.

Table 6 Units Units
E10, LHV 112114 Btu/gal 31.25 MJ/L
EPA combined 28 mile/gal 11.905 km/L
Steady speed 65 mile/h 104.607 km/h
Fuel 2.321 gal/h 8.787 L/h
Energy 260217 Btu/h 274.55 MJ/h
Time 3600 s 3600 s
Supplied power 76.27 kW 76.26 kW
Tank-to-wheel efficiency 0.219 0.219
Upstream factor* 1.2639 1.2639
Source-to-wheel efficiency 0.173 0.173

* The well-to-tank upstream factor accounts for the energy used for exploration, extraction, processing and transport of the E10 fuel. See Table 7.

Table 7 E10
kg CO2/L
Combustion 2.271
Extraction 0.240
Transport 0.030
Refining 0.300
Distribution 0.030
Total 2.870
Upstream factor 1.2639

http://www.cleanskies.org/wp-content/uploads/2011/06/staple_swisher.pdf

http://www.afteroilev.com/Pub/CO2_Emissions_from_Refining_Gasoline.pdf

http://energyoutlook.blogspot.com/2008/08/back-door-on-co2.html

http://www.reuters.com/article/2009/07/28/oil-cost-factbox-idUSLS12407420090728

http://www.accenture.com/SiteCollectionDocuments/PDF/MOD-019_CarbonAccountingPoV_083010_LR.pdf

https://www.vcalc.com/wiki/MichaelBartmess/CO2+from+Diesel+Fuel

NOTE: The UK, cleanairchoice and GREET claim the factor is 1.203, 1.23 and 1.2568, respectively. In this analysis 1.2639 was used which attributes more CO2eq to E10 vehicles, which makes EVs look better, in comparison. See Table 2 in second URL and Page 8 in third URL.

http://www.lowcvp.org.uk/initiatives/leb/TestingandAccreditation/WTTFactors.htm

http://www.cleanairchoice.org/fuels/E85C02Report2004.PDF

https://www.arb.ca.gov/fuels/lcfs/lcfs_meetings/12132016wang.pdf

Source Factor for US Electrical System: Various fuels, extracted from the earth, are fed to US electrical power plants. For exploration and extraction mostly diesel is used, for processing mostly diesel, gas and electricity are used, and for transport mostly diesel is used.

Table 7 shows the well-to-pump source factor for E10 is about 1.2639. The well-to-user source factor for gas and the mine/well-to-meter source factor for electricity are about 1.090 and 2.8776, respectively.

Also there is the energy consumed for O&M and on-going replacements/upgrading of the infrastructures used for exploration, extraction, processing and transport of the source energy that is converted to primary energy for the US economy. The US electrical system uses about 40% of all primary energy.

This results in an upstream factor of the US electrical system of about 1.08, i.e., the equivalent of about 8% of the source energy is used to obtain the primary energy fed to power plants. That 8% usage causes CO2 emissions. See Table 8. Excluded is the embodied energy of all the required infrastructures.

The Source-to-Wheel Efficiency of an EV

The US economy was supplied with about 25,451.00 TWh of primary energy in 2013. See Table 8. In this analysis, I used the 2013 emission data in conjunction with the 2013 electricity generation data.

The EIA 2013 emissions data is higher than at present, due to gas replacing coal. It is ironic, I could find the 2016 GERMAN electricity generation data, but not the 2016 US data.

https://en.wikipedia.org/wiki/Energy_in_the_United_States

Table 8 % TWh
US Primary energy 25451.00
Electrical fraction 0.40
Electrical primary energy 10180.40
Gross generation 4227.62
Self-use, % of Generation 3.82 161.55
Net generation to grid 4065.97
Conversion factor 0.3994
Imports, % of net generation 1.15 46.74
To grid 4112.71
T&D, % of To grid 6.50 267.33
To electric meters 3845.38
System efficiency, PE basis 0.3777
Upstream factor 8.00 0.9200
System efficiency, SE basis 0.3475
EV efficiency
Inverter AC to DC 0.950
Battery and charger 0.800
Motor and drivetrain 0.900
Meter-to-wheel 0.684
Source-to-wheel 0.228

German 2016 Electrical Data: Here are the corresponding numbers for Germany. In 2016, domestic electricity consumption = gross generation (648.4), less self-use (30), less net exports (53.7), less transmission and distribution (30), less pumped storage and misc. (19.4), = about 515.3 TWh at user meters. (CO2 of the gross generation) / (515.3 TWh) = grid CO2 intensity at the meter, which should be multiplied by the kWh drawn by an EV. However, this CO2 is based on primary energy grid intensity. It has to be adjusted by a factor to get source energy grid intensity, similar to the Table 8 procedure.

http://www.ag-energiebilanzen.de

CO2 Emission Reduction Due to less Coal and More Natural Gas Combustion: 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. See Table 9.

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

Table 9 2016
CO2, MMt 1821
To meters, TWh 3845.38
kg CO2/kWh 0.4736
lb/kg 2.20462
lb CO2/kWh, PE basis 1.0440
Upstream factor 1.08
lb CO2/kWh, SE basis 1.1275

Photo Credit: Frank Hebbert via Flickr

Willem Post's picture

Thank Willem for the Post!

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Discussions

Roger Arnold's picture
Roger Arnold on May 14, 2017 8:27 pm GMT

EVs and PHEVs, all have on-board chargers. Their plugin connections are AC. AFIK, none have options for DC input. So bypassing the PV system’s inverter is not an option.

That doesn’t mean that a home charging system can only take power from the grid. If it taps the PV system’s inverter inboard of the utility meter, power flow will be from the PV panels, through the inverter, then to the vehicle and its on-board charger.

Roger Arnold's picture
Roger Arnold on May 14, 2017 9:21 pm GMT

Willem,

Sorry, maybe my brain has gone AWOL, but those statements aren’t making any sense to me.

You’re apparently making a distinction between “source energy” and “primary energy” that I haven’t encountered before.

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 12:02 am GMT

Now Illinois can send excess power to Cleveland, if necessary.

What you’re missing is any concept of quantity.  There’s a limit to the power you can send through a line.  For an AC line, that limit is substantially less than V²/(2Z).  Most of the series impedance is inductance, which causes voltage drop and phase shift but does not consume power per se; however, the phase shift is an issue.

An AC line transfers power from the end with leading phase (NOT higher voltage!) to the one with lagging phase.  The power transfer increases with phase shift until you hit the magic number of 90°.  More than 90° phase difference and the power transfer DECREASES.  At the load end, the power draw of the loads drags the phase further behind (slowing generators down) while the less-loaded generators at the supply end speed up, and the two ends go completely out of sync.  Massive surge currents would result.  The SCADA systems would trip the circuit breakers by that point, though.

The upshot is yes, you CAN move a certain amount of power from Ames to Chicago to Cleveland to Buffalo and on eastward.  The niggling detail is that “a certain amount of power” is pretty small compared to what you’d need to move.

Those long lines are generally intended to let relatively nearby load centers trade off different demand peaks and share spinning reserves.  The system is neither intended nor built to let the wind belt run the country, and really can’t do it.

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 3:51 am GMT

Willem, if you know what is going to a grid at a certain moment, you know what is coming out. The balance is identical to what’s going in.

If 50% of a grid mix is being contributed by natural gas,12% by nuclear, 8% by renewables, and 30% by coal at a specific moment, everyone using electricity, on that grid, at that moment, is getting 50% of their electricity from the combustion of natural gas. That the components of electricity can’t be broken apart and identified after mixed together does not erase its provenance, nor the emissions footprint of that provenance.

I had one year of physics in high school, and I don’t think I can make it plainer than that.

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 5:22 am GMT

1) That would require DC (from the solar panels) to go to a DC charge controller on the EV battery

No.  It only requires the power to bypass the meter.  Any household with net metering and an EV plugged in to charge will send its self-generation to the EV before any passes to the wide world outside.  That generation will “disappear”, and can only be inferred by absence of load.

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 5:29 am GMT

EVs and PHEVs, all have on-board chargers. Their plugin connections are AC. AFIK, none have options for DC input.

Behold the Combo connector which allows DC charging at up to 200 amperes.  This removes all of the AC-DC conversion from the vehicle.

As of 2 years ago, the American-model BMW i3 was factory-equipped with a combo charging connector.  I cannot say about Leafs, Volts and whatnot as I have not looked at any closely.

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 5:38 am GMT

I studied physics at near-PhD level at RPI.

I studied the actual physics of motors and the magnetic properties of core steels as part of my education in electrical engineering.  I still remember how to do the analysis of reactive power, power factor and phase shifts on power lines (phasor analysis).

Unless you pick that up yourself, you’re not nearly as informed as the guy with a BS who’s sitting in the control room at an ISO somewhere watching the states of plants, lines and substations.  He knows how physics applies to the grid, and you don’t.

Roger Arnold's picture
Roger Arnold on May 15, 2017 6:25 am GMT

Thanks, EP. You’ve enabled me to exceed my “learn something new every day” goal for the day.

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 6:34 am GMT

EP, thanks for explanation of how power is increased on an AC grid (leading phase). Re:

At the load end, the power draw of the loads drags the phase further behind (slowing generators down)…

Where (and why) would there be generators at the load end?

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 7:22 am GMT

Where (and why) would there be generators at the load end?

Everywhere.  Load centers (like cities) usually have generation local to them because that’s most efficient (e.g. Monroe’s 3400 MW plus Fermi II are just a few miles from Detroit).  Longer lines interconnect load centers so they can trade off load peaks at different times of day and share spinning reserve.  The “source” and “load” ends of such lines change places regularly.  In the case of lines from mine-mouth power plants this is not the case, but those are a relatively recent development compared to the age of the grid.

Ironically, the “hoteling” power of wind farms mean that they become loads when they are becalmed.

Willem Post's picture
Willem Post on May 15, 2017 9:07 am GMT

Bob,

Single-minded?

The article, “Is Ethanol a Cost Effective Solution to Climate Change?” shows, after a detailed analysis of the GREET computer program, the Argonne analysts relied on less-than-fully accurate international data bases, and overestimated well-to-wheel fossil fuels consumption (and associated CO2 equivalent emissions) of petroleum fuels by up to about 9%.
http://www.theenergycollective.com/jemiller_ep/172526/ethanol-cost-effec...

Willem Post's picture
Willem Post on May 15, 2017 9:18 am GMT

Roger,

It is a common concept in life cycle energy analyses of pathways and of Energy Return / Energy Invested, EROEI, analyses.

Argonne and everyone else uses it, already for decades.

Willem Post's picture
Willem Post on May 15, 2017 9:31 am GMT

EP,

I agree with your description.

“Those long lines are generally intended to let relatively nearby load centers trade off different demand peaks and share spinning reserves. The system is neither intended nor built to let the wind belt run the country, and really can’t do it.”

Germany is sending its excess energy (on windy days) via Denmark to Norway, about 700 km away, for balancing by Norway’s hydro plants, already for about 20 years.

Denmark does the same, so does the UK.

It is a matter of transmission system design.

During the last 20 years more and more HVDC lines have been installed to reduce/eliminate impedance and inductance issues.

The US is way behind Europe regarding HVDC.

Plans are to install up to 6 HVDC lines (one is under construction) between the US northeast and East Canada, which has at least 10,000 MW of surplus hydro.

Willem Post's picture
Willem Post on May 15, 2017 9:34 am GMT

EP,

“Ironically, the “hoteling” power of wind farms mean that they become loads when they are becalmed.”

Wind turbines use energy for self-use, even when not producing, but so do all other power plants.

Willem Post's picture
Willem Post on May 15, 2017 9:47 am GMT

Bob,

Energy is Joules, i.e., energy

Power is Joules/second, i.e., a RATE of energy; big power plants have higher rates than small ones.

EP is referring to AC having transmission limits due to impedance and inductance, which in Europe is being dealt with using HVDC lines.

If, per Jacobson (a trained environmentalist, not a power systems analyst), the US were “to do it all” with wind and solar, the US would need an HVDC overlay system including covering parts of Canada and Alaska, at least a $500 billion item, to make sure US southwest stored CSP energy would be everywhere, 24/7/365.

In an email series with Jacobson, I had to explain his scheme would not work without it.

He had not included it in his cost estimate.

Willem Post's picture
Willem Post on May 15, 2017 10:01 am GMT

Bob,

Grids are connected to each other and are interchanging energy, so provenance becomes blurred.

Norway consumes German excess energy during windy periods, even though on average, 98% of Norway energy is generated with hydro. Norway merely dials back its hydro units to balance frequencies and voltages.

The only thing on the various grids is electromagnetic waves, which cannot be identified, as being this or that, by any measurement.

If your own PV system, feeds your own batteries, which charge your own EV, then you can say for sure: “my EV runs on my solar energy”

Willem Post's picture
Willem Post on May 15, 2017 10:12 am GMT

“No. It only requires the power to bypass the meter. Any household with net metering and an EV plugged in to charge will send its self-generation to the EV before any passes to the wide world outside. That generation will “disappear”, and can only be inferred by absence of load.”

That “self generation” is AC or DC?,

If AC, then the inverter of the vehicle will convert it to DC, then send it to the charge controller, then to the EV battery?

If DC, then it will by-pass the inverter on the vehicle and directly go to the charge controller?

Willem Post's picture
Willem Post on May 15, 2017 1:42 pm GMT

Bob.

The BC carbon tax is no longer revenue neutral.

It started out that way, with much rah, rah, but, as usual, stuff happens.

Willem Post's picture
Willem Post on May 15, 2017 2:20 pm GMT

Civilitas,

I agree, the EIA 2013 emissions data is higher than at present. I used that data in conjunction with the 2013 electrical system data.

It is ironic, I could find the 2016 GERMAN electrical data, but not the US 2016 data.

I will make a note in the revised issue of this article, which will be posted soon.

Regarding consumer choice: It shows, the US is still somewhat of a free country.

That “un-PC” consumption could be reined in with a new federal agency: The US Consumption Preferences Authority.

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 2:51 pm GMT

I agree Willem, provenance is becoming blurred, much like candy bars of a century ago, when manufacturers added floor sweepings as filler, or the oft-quoted “you don’t want to know how the sausage is made”. There’s no technical reason why it needs to be.

Renewables activists would like to consider Norway’s consumption of excess German energy “clean” merely because it coincides with periods of excessive wind generation in Germany. But every kW imported to Norway from Germany has a lignite component, a methane component, etc. corresponding to whatever happens to be contributing power to the German grid at that moment. To know how clean German energy entering Norway’s grid is, you’d need an accurate accounting of Germany’s grid mix in real time. Not rocket science – but like any science in 2017, it’s vulnerable to manipulation by political forces beyond Norway’s control.

The “blurring of provenance” happens to be a big issue in California right now. As our Air Resources Board celebrates maintaining status quo on carbon emissions and champagne corks fly at the Sierra Club, 30% of CA electricity is coming from outside our borders, with 10% officially “of unknown origin”. If California joins the Western Interconnection and even more energy from outsourced generation crosses our borders, we’ll be reliant on the WI system operator for an accurate accounting of its grid mix in real time. Also not rocket science – but with $billions at stake, our state will be more vulnerable than Norway to manipulation by political forces beyond its control.

As the clamor for distributed energy grows and our electricity supply can be increasingly likened to “energy sausage”, we can’t afford to dismiss the importance of an accurate accounting of its ingredients.

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 3:52 pm GMT

No argument there, Willem. When Jacobson’s “A Plan to Power 100% of the Planet with Renewables” appeared in 2009, I saw an easy target. Shooting fish in a barrel – not the birth of a Renewables Messiah.

But I saw Donald Trump in a similar light, so what do I know?

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 4:29 pm GMT

Willem, when I see critcism of the “GREET computer program” I see someone who doesn’t understand what a model is. If you believe Argonne defaults relied on “less-than-fully-accurate international data bases” or “overestimated well-to-wheels fossil fuels consumption” you must either 1) believe fully-accurate international databases exist, or 2) have knowledge of more reputable/accurate data from somewhere else. If so, just plug in your own inputs and hit Enter.

But if you’re going to challenge GREET defaults, it’s your responsibility to show why – not theirs.

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 4:57 pm GMT

That “self generation” is AC or DC?

If it’s PV, it starts as DC. Why are you asking silly questions?  The issue is whether the customer with a roof of PV panels and an EV would have lots of energy that never gets measured by the system.

It’s possible that a customer with an EV would install a fast DC charger.  Not too likely, but possible.  But what’s the likelihood that such a charger would have a connection for PV input?  Who’d add extra cost to be able to charge from PV at 5 kW when the whole point of the charger is to be able to pump 50 kW?

The most likely outcome is that the PV output is inverted to AC (the “common currency”, or maybe I should say “current-sy”), goes into the main panel, then out another breaker to the EV’s AC charger.  It never goes through the meter and so doesn’t get counted.  People will just accept the losses in the double conversion for the sake of not adding extra cost and complexity.

Willem Post's picture
Willem Post on May 15, 2017 8:52 pm GMT

Bob,

Over the years John Miller, who wrote the article, has posted many articles on TEC, as have I.

I trust his judgement.

He may have taken it up with the Argonne folks, but gotten nowhere, as happened to me when I took issue with USDA data, regarding my Corn to Ethanol article some years ago.

Plugging numbers into a computer program is a fool’s game, if you do not know the step by step how the program arrived at the results.

Simply do this or that does not cut the cake with me and likely not John Miller.

Willem Post's picture
Willem Post on May 15, 2017 9:05 pm GMT

Bob,
Jacobsen presented his study at the Paris conference and was lauded by what I call official idiots.

Willem Post's picture
Willem Post on May 15, 2017 9:07 pm GMT

Bob,

All this energy stuff was not a concern, until the government/do-good politicos started to get involved helping various dreamers to save the world.

With 10 billion people, it will go to hell in a hand basket anyway.

Willem Post's picture
Willem Post on May 15, 2017 9:18 pm GMT

EP,
I agree with the way you describe it.

“People will just accept the losses in the double conversion for the sake of not adding extra cost and complexity.”

I guess they will, as most of them do not know, or do not care, about the losses, in their eagerness “to be green”.

The PV energy from DC to AC by the PV inverter, about a 5% loss, then as AC to the EV charger, then turned into DC by the EV inverter.

That is a lot of losses.

Engineer- Poet's picture
Engineer- Poet on May 15, 2017 9:42 pm GMT

FYI:  Inverters are DC-to-AC devices, so called because they invert the usual way of things.  There are DC-DC converters which boost or buck a supply to a higher or lower voltage, sometimes bidirectionally.  The usual name for an AC-line to battery device is a charger.

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 11:02 pm GMT

Willem, though government/do-good politicos could be blamed for preventing indiscriminate lynching of people for the color of their skin; for shipping soldiers to the beaches of Normandy in 1944; for building the Interstate Highway System, etc. etc. etc. etc. etc…, I think they slept ok.

To all the people who believe none of that stuff was a concern, who never lifted a finger to try to change things because they thought a) they didn’t need to b) the world will go to hell in a hand basket anyway, dreamers like me have but one thing to say: you’re welcome.

Bob Meinetz's picture
Bob Meinetz on May 15, 2017 11:22 pm GMT

Willem, as much as I disagree with pretty much everything Jacobson has to say, at least he got off his ass and flew to Paris to argue for something in which he believes.

What did you do today?

Willem Post's picture
Willem Post on May 16, 2017 12:01 am GMT

Bob,

That trip, staying at 5 star hotels and wined and dined and admired by the eco folks, and emitting a lot of CO2 and hot air, did not cost him a dime, and cost us plenty.

The conference was held before the tourist season started so as to maximize revenue to Paris businesses.

Bob Meinetz's picture
Bob Meinetz on May 16, 2017 12:18 am GMT

Willem, that’s horrible. Have you spent a dime to oppose him?

Silence is compliance.

Darius Bentvels's picture
Darius Bentvels on May 16, 2017 1:48 pm GMT

Bob,
That would not have made a dime difference.
The power of economics gradually take over and turns Jacobson’s vision gradually into reality. Though it may take until the second part of this century.

Btw.
Jacobsen may have copied a lot from the greens in Germany, who fight the whole nineties to make their vision reality.
Many were disappointed when they only could reach agreement with the SPD regarding:
– all nuclear out asap (that was fine)
– 80% of all electricity renewable in 2050 (too slow)
– 60% of all energy consumption renewable in 2050 (too slow).

Though Schröder (SPD who became Bundeskanzler) could convince that it was better to have a slow but sure transition than a fast one which would sink as German population wouldn’t be prepared to pay the huge costs (solar was then €700/MWh, etc). The argument was that those costs would come down by creating a mass market (which occurred) but that such would take decades…

He was supported by the repeated outcome of studies by a.o. renowned international consulting firms (also about how to arrange things). Probably “international” because those were thought to be less biassed.

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