Revised and updated, to bring up-to-date feasibility of the EV cars, year 2025.
Hirsch Vivat P.E. M.Sc. Auto-transport & mobile equipment.
That article discusses total real overall energy efficiency WTW of Electric car (EV) in comparison to the Gas powered (ICEV) based on CO2 polution.
There are worldwide registries of 1.474 billion cars and only 2.4% are EVs. (Jan. 2024). EV sales are rapidly increasing (2024).
Comparison of the Overall Energy Efficiency of internal Combustion Engine Vehicles vs. to EV will be calculated by using identical fuel. This is an “APPLE TO APPLE” approach. The benefit of renewable energy will be added in consequences calculations, page 4.
Energy efficiency of "Refinery" producing Fuel oil for Power Plants and Gasoline is about equal. (94.5% vs. 88.6%) or 1.07 ratios. The fuel oil #4 for power plants has a higher BTU content per gallon than gasoline on 1,137 ratios. The difference between them will be added in "total energy efficiency calculations"
-The Total Energy Efficiency of EV is a multiplication of three components: (efficiency of the Refinery) x (efficiency of the Power Plant and Power Grid) x (efficiency of the EV car itself). Or “Refinery -- to Power plant and Grid -- to the wheels”
-Total Energy Efficiency for the gas-powered vehicle is a multiplication of two components: (efficiency of the Refinery) x (the ICEV car efficiency). Or “Refinery -- to the wheels”
- In both cases the “Well” to - “Oil supply”- to “Refinery” is equal values for EV and ICEV and it cancel each other; Calculations will start for both vehicles equally, from “Refinery” to - "the Wheels”.
Efficiency vs. energy consumption on gas-powered vehicle is RELATIVELY STABLE, when efficiency vs. energy consumption of EV is VARIABLE and it depends on the weather temperature, battery age, power plant fuel source, and added percentage of renewable non-fossil energy. In all published work of EV study a brand new EV is selected for testing and calculation? It is wrong; 6 years old EV with original used battery and 70000 mi mileage should be used for calculations and testing! The average age of a car on US roads is now 12.2 years.
Average Power plant efficiency running on oil is n= 0.39; it happened to be about the same value as the average world efficiency of power generation n=0.40; power generation in USA n=0.40 Ref.16 U.S. Renewable Energy Factsheet | Center for Sustainable Systems (umich.edu)
Scope, calculation & summary. “Efficiency” in engineering is measured by “ratio of useful output to total input” and designated in percentage or ratio coefficient (n=1 is equal to 100%). In most articles you may find non-engineering efficiencies which are measured in miles, watt hour per mile (Wh/mi) , MPGe, gas prices vs. electricity price, all calculated and tested at ideal non variable invariament. It is misleading and cannot be used for engineering assessment.
TOTAL ENERGY EFFICIENCY CALCULATION OF EV can and should be done by using the “SYSTEM OF MULTIPLE COMPONENTS” : (regenerative breaking is not included in the calculations for a reason that it can be used with on-off switch at selected conditions. Has little benefit on highway and at low temperatures. 1) For purpose of “apple to apple” comparison Total efficiency of power plants is taken n=0.40 2) Efficiency loss of electrical transmission through the electrical grid is 6 % or efficiency factor is n=94;
3) Efficiency loss of electrical car battery is 10% when is charged. Charging efficiency factor is n= 0.9;
4) Efficiency loss of an electrical car battery when discharged is 10%, efficiency factor is n= 0.9;
5) Efficiency loss of an electrical battery when temperature falls below -20 C is n=0.60-0.65 for a 6 years old battery. Ref#2 For calculation we will take n= 0.85 (not everywhere and not all the time is winter.)
6) Efficiency loss of 15% of electrical power used for heating or A/C, efficiency n=0.85;
7) Mechanical efficiency: only n=0.90;
8) Finally efficiency of an EV electrical motor is n= 0.90 (.80 -.94) Ref #6
9) Battery efficiency for 6 years old battery is n=0.80 (Battery life is about 10 -12 years).
10) EV “Charging invertor’’ from AC to DC has efficiency factor n=0.95;
Ref#13 Battery degradation results for our base EV and AEV for the composite... | Download Scientific Diagram (researchgate.net)
Efficiency calculations are made without adding 10-14 metric ton of the CO2 emission as a result of manufacturing the lithium-ion batteries; However CO2 battery footprint emission will be added for obtaining the TOTAL EFFICIENCY based on CO2 EMISSION on a page 4.
NOW WE CAN CALCULATE THE TOTAL GLOBAL EFFICIENCY OF ELECTRICAL CAR, BASED ON OIL POWER PLANT GENERATION. (“Apples to apple” approach): Total EV efficience based on “global” electric power generation at the cold winter for a 6 years old EV is:
1.137 x 1.07 x 0.40 x 0.94 x 0.9 x 0.9 x 0.85 x 0.85 x 0. 90 x 0.90 x 0.80 x 0.95= 0.17 It looks that gasoline powered car today at the same conditions is a bit more efficient device than 6 years old EV when is driven by using identical fuel at winter as ICEV. Most of the EV efficiency studies are done within speed range from 0 to 100km/h. Only in a few studies you may find that additional energy of 40% is required to reach speed 140km/h or 25% additional energy required more than gas-powered car. That means that EV efficiency on high speed will drop even farther down. Using the same approach but for a brand new EV at ideal conditions without using A/C or heater with added regenerative braking EV efficiency may reach 0.28-0.32, which is the same efficiency as latest ICEV models (028) or (diesel 0.37). Ref #12 https://www.researchgate.net/figure/ehicle-energy-economy-at-different-speeds_fig1_326822085
EPA is testing EVs only till 104 km/h, it is very low! 140 km/h would be acceptable. When regenerative braking is used it will add15% to battery power; it will raise the total efficiency only to 0.20 at the winter conditions: [0.17 : O.80 x (0,80 + 0.15)] = 0.20
Discussion: Based on above calculation efficiency for 6 years old EV at the cold winter or hot summer is 0.20 . For gas-powered Cars (fuel tank- to- wheels) efficiency is reaching to 0.28 for new models (diesel powered is reaching 0.37). See Ref#15. The EV CONS are: high initial cost and maintenance, battery replacement cost, power loss by aging, less efficiency on the higher speed, additional weight of 1000 lb., charging time, blackouts. Travel for long distances on EV is not recommended. Ref#2 (See axle overload to asphalt pavement and EV tire wear Ref#14 . One of the most noticeable PROS of EV is reduction of the LOCAL CO2 pollution reverting it to the power plant chimney when running on fossil fuel and CO2 reduction when renewable portion of energy is added. Actual and total CO2 emission should be the main concern when buying an EV or Hybrid.
Total worldwide electricity production consists of 27% renewable, 10% nuclear and 63% of fossil fuel. 37 % of non-fossil is divided by: 1/3 from “other sources”, 1/3 from nuclear and the rest from hydro plants build 10-70 years ago. It took more than 20 years to build up energy generation from “other resources “(solar, wind, thermo). The new “project” is to convert worldwide remaining 63% of fossil fuel generation to renewable for 20 -30 years! Entire Electrical Grids (Globally) would be reconstructed and also expended to generate additional electricity to operate EVs. 5 out of 8 billion people are inhabitants of the relatively poor countries and would not be able to contribute funds for such mega-project. All western countries are responsible for 25% CO2 emission. For the next 12 years a HYBRID vehicle would be a better choice. Hybrid car is more reliable with lower CO2 emission. It may take another 10-15 years to produce a reliable EV car with a better charging system. EV battery is very expensive to produce and dispose. EV Battery last about 12 years at the range of 100000 - 200000 mi with the efficiency loss of 0.65 on the end of battery life. Cost of the EV battery is $16000 plus replacement cost. Disposal of lithium batteries can be hazardous for the environment. Ref#4https://8billiontrees.com/carbon-offsets-credits/carbon-footprint-of-lithium-ion-battery-production/
In the future EV market may be divided by two groups: one being able to afford a new expensive EV and another group would be left to buy used EVs with replaced batteries. So far the industry is in process to find sustainable batteries which will last 16-20 years.
Conclusion: My statement is valid only if all undersigned countries of the Paris Climate Agreement will be in compliance of all requirements. To predict global transition to EV is challenging and unpredictable. My TAKE: The future (20-25 years) of the Global auto transportation: the larger part of transportation sector will be taken by PLUG-IN HYBRID vehicles ( ref# 17 Ensuring greenhouse gas reductions from electric vehicles compared to hybrid gasoline vehicles requires a cleaner U.S. electricity grid | Scientific Reports (nature.com) ) , next will be EV cars , the rest will be vehicles with high efficient turbocharged gas or/and diesel powered engines, shared with HYDROGEN powered vehicles. (EV HUMMER, EV F-150 and TESLA CUBERTRUCK are not going to save the planet). A hydrogen vehicle does not require charging, it would not overload the Grid to some degree.ref#18 Optimal design of grid-connected green hydrogen plants considering electrolysis internal parameters and battery energy storage systems - ScienceDirect. Refuelling of Hydrogen vehicles will take couple minutes and would be performed on already existing gas station. Total transportation sector is contributing 21% pollutions globally; Road transportation 15.5%. Cars, motorcycles and vans are contributing only 7.6% pollutions globally. As it is projected, 25 years from now car sector 7.6% will drop down to 4.0% globally by implementing EVs. Landfill and water pollution from the battery manufactories and disposal will become in some countries unmanageable. Semi-trailers responsible for 2% of global pollution temporary would be and can be left as it is. Last models of semi-trailers powered with new diesel engines are significantly more efficient and with fewer pollutant. Ref11. However maritime shipping as a part of transportation is responsible for 3% of the global pollution would be difficult to convert to electrical; new mega-large vessels may become nuclear powered. Aviation transport is 2.5% of the world CO2 emission. The necessity and demands to achieve the 3.6% reduction of CO2 pollution for the passengers cars are stated bellow: there are 280 million registered vehicles in USA and 1.47 billion cars worldwide for now and that amount will grow. It is projected worldwide electrical energy will double up for the next 30 years. It would be very questionable to achieve that without adding Nuclear Power Plants. FAST Supercharging stations for trucks (350 KW 480V) may cost $50,000 per charger or more with additional high cost connecting them to the Electrical Grid; EV would require 50 KW per one FAST charger or slow overnight car charger only 10kw at home. Fast charging stations (level 3) require 4-5 times more energy demand from the Grid than SLOW charging stations (level 2). Fast charging systems will require additional Grid enlargement to fasciculate that demand. When only 20% of all registered vehicles in USA will be converted to EV a charge during one or two days would require, 28 million home chargers and 3 million public charging stations would be installed. That might not happen in other countries where citizens do not own detached homes with double garages. Other countries will need more public chargers. The cost of the global grid upgrading for 2035 is estimated to reach 2.5 trillion dollars (IEA). There are a lot of approximate not approved estimates by 195 countries including USA. Industry is trying to solve the inefficient battery performance by introducing new and better battery storages for EV. New inexpensive energy storages will make EV more attractive for consumers and better for environment; however it would not lower the pollutions emitted by the Power Plants running on fossil fuel. Finely, when new high efficiency battery storages will be introduced and implemented by industry, my “study” would not become obsolete, it would be updated to reflect the positive impact of the new technology.
Ref#2 https://www.mdpi.com/2313-0105/10/3/107
Ref #3 https://www.ieso.ca/en/Learn/Ontario-Supply-Mix/Ontario-Energy-Capacity Ref #5 Everything You Need to Know About the Fastest-Growing Source of Global Emissions: Transport | World Resources Institute (wri.org) Ref #6 https://x-engineer.org/automotive-engineering/vehicle/electric-vehicles/ev-design-electric-motors/ Ref #7 IEA international energy agency. (Neither IEA or SAE international haven’t issued any standards for the total EV efficiency testing. SAE so far has only standards for charging (connective elements), battery energy consumption for 5 range cycles tests and EV vibration test. SAE is using only new EV components. Only EPA is providing a 5 cycle “fuel economy” test inside the building on dynamometer using maximum lower temperature -7C (20F) and max speed 104 km/hour (65m/h). In my opinion a 6 years old EV with 70000mi should be stored and tested at -20C (-4 F) at the speed reaching 140km/hour (87m/h) with the heater “on”. EV should be charged at -20C without preheating battery (manually or automatic); If preheating procedure is selected, energy used for preheating should be added as an efficiency loss. Finally EPA conclusions are based on non-compatible comparison between “receptacle - to-wheels” of EV vs. “well-to-wheels” for a gas-powered car. Those misleading results are advertised without mentioning, that electric generation in USA is still originated from 59% of burning the fossil fuels. Test results by EPA are wrong and misleading. (See Page 4, USA). Electric cars are only as clean as their power supply. Ref # 9 Fuel Economy and EV Range Testing | US EPA Ref#10 Comparison of the Overall Energy Efficiency for Internal Combustion Engine Vehicles and Electric Vehicles (sciendo.com) Ref#11 Advantages of Diesel Engines | Cummins Inc. Total global “road transportation” is contributing 15.5% OF CO2. (Total transportation sector is 21%) CARS, MOTOCUCLES, VANS as a subsector are contributing only 7.67% ; All other global sectors responsible for remaining 79% of CO2 EMISSION. It is predicted by UNFCCC that at 2050 year 700 million cars globally will be EV and WORLD power plants will be 8o% non-fossil fuel effective; that will decrease CO2 and other greenhouse gasses emission. The “car” sector CO2 pollution will drop down to 4.0% from the 7.67 % it is a great achievement and used by politicians as the most important subject for the public discussions avoiding or lessen conversations for remaining 79 % CO2 pollution of the “other sectors”. Ref#8 https://www.epa.gov/ghgemissions/global-greenhouse-gas-overview
. RESULTS: PAGE 4 TOTAL EFFICIENCY based on CO2 EMISSION.
One of the main purposes of EV is reduction of harmful emissions. In subsequent calculations the non-fossil amount of efficiency will be assumed as 100% effective and not being added in calculations, only efficiency from the power plant to the wheels of EV will be calculated. However CO2 battery footprint emission will be added for calculations; it adds 27% of hazardous emission per year, based on the EV lifespan. Ref#4. ICEV yearly emission is 4.6 ton CO2 per year. EV may last 12 years. Annual emission of CO2 as a result of battery manufacturing (14 : 12) : 4.6 = 27%). As additional information to that study most likely that replaced battery may perform less than 12 years, in that case the annual added EV battery footprint may be increased to 40%. It would drastically reduce the TOTAL EFFICIENCY based on CO2.The subsequent calculations are conservative (the secondary battery is not added). EV tires wear is 30% higher (not added) Ref#14 Road Hazard: Evidence Mounts on Toxic Pollution from Tires - Yale E360
1) ONTARIO, CANADA ; 28% OF THE GENERATION IS PRODUCED BY FOSSIL FUEL (OIL AND GAS, ABOUT 50/50 with the plant efficiency of 0.415). THE CO2 EMISSION COMES FROM 29% OF FOSSIL FUEL. Adding numerical number of 27% to CO2 emission as a result of battery manufacturing will increase the total percentage to 55%. Calculation on the page 2 is based on 100% use of fossil fuel. Adding 45% of non-fossil fuel (1 – 55 = 0.45) will change the outcome of the equation as it is shown : for “non-ideal” condition: (0.17 x 0.55)+ (0.17 x 1/0.415 x 0.45) = 0.28 and “for ideal” condition: (0.30 x 0.55) + (0.30 x 1/0.415 x 0.45)= 0.49 The average will be (0.30 + 0.49) : 2 = 0.40 There some contribution of using an EV in Ontario; it will reduce pollution to 40% and it will totally eliminate the local CO2 emission at heavy slow moving city traffic. The plug-in Hybrid will reduce pollution by 25-35% just a bit less than EV percentage but without larger demand of electricity from the Electric Grid. Consumer shell read CONS and PROS described on the page 2. (EV may require the battery replacement in the future which may drastically increase the CO2 emission). Taking in account the high EV price and EV CONS the Plug-in HYBRID may be the first choice in Ontario, second choice would be EV. However, EV may become the first choice when it is used durng the long day in a heavy slow traffic and charged during the night on a slow 10kw charger. For BC and Quebec the EV will be the best choice for the reduction of harmful emissions. Alberta is using 89% of fossil fuel for electro generation; obviously EV would not be effective there at all. Canada is using at average 21% of fossil fuel.
2) California: 46.5% electricity is generated by natural gas; adding 27% of CO2 emission as a result of battery manufacturing will increase the total percentage: 46.5 + 27 =73% Calculating using the same approach as above, the efficiency responsible for CO2 emission will fluctuate from 0.22 to 0.40 or average 0.32. Plug-in Hybrids is justified in California. However EV will not be justified. 3) USA is using in average 59% of fossil fuel to generate electricity (2024) , with the exception to Maine, Vermont, Washington state, partially California and South Carolina. Adding 27% of the harmful emission as a result of battery manufacturing will increase the total fossil emission higher. Finally EV is not feasible to use in USA for now, Plug-in-Hybrid and latest ICEV models will be a better choice. At mentioned states with lower fossil fuel emission EV may be acceptable as a first choice.
4)France: 7% fossil, 70% nuclear, 23% renewable. EV in France counts as a “clean car”.
-The EV efficiency on the EPA “stick-on” label is wrong and misleading and obtained using “receptacle-to- wheels” approach. It is ignored that 59% of US energy is generated by burning fossil fuel (21% in Canada). Only “well-to-wheels” method will evaluate the total efficiency correctly. Additional QR code on the stick-on car label can be added and used for “well-to-wheels” method to evaluate efficiency of the EV based on CO2 harmful pollution at the location where QR code is scanned. It is amazing that the EPA has come up with a measuring unit MPGe and Wh/mi that is based on converting an invariant unit to some arbitrary equivalent based on "equivalence" of energy; it is totally incorrect and misleading! (MPGe is mainly used in USA). Finally, measuring efficiency units should be alike to European Union and the rest of the world using EEA unit counting CO2 in g/km. EV is “certified” by EPA as a “Zero-emission-vehicle” (ZEV) which is totally wrong and misleading. (European Environment agency EEA and the rest of the world do not have such non-technical invalid “certifications”, Europeans just call it LEV (low emission). There are no any EV in USA, Mexico and Canada which are not emitting CO2. EV pollutants are just reverted to the Power plant chimneys; also battery carbon footprint is a part of the EV pollutants and should be included in CO2 harmful EV emission. One of the main purposes of EV is reduction of harmful emissions. When renewable and nuclear energy will account for 60% or higher EV will become more justifiable. See Ref#19 and Ref#20
Ref#20 Which countries get the most electricity from low-carbon sources? - Our World in Data