For coal power plants:
electric_car.efficiency
100 miles per 34.6 kWh
The "gas mileage" equivalent for an average electric car.
Average Electric Car kWh Per Mile [Results From 231 EVs]
ecocostsavings.com › average-electric-car-kwh-per-mile
li_ion.charge_discharge_efficiency
85%
When you charge a lithium-ion battery, this much of the energy can be recovered. The rest is lost as heat.
Range: 80 to 90 %
from wikipedia; haven't found original source yet
power_grid.losses
5%
Electricity lost in transmission & distribution
Frequently Asked Questions (FAQs) - U.S. Energy Information ... - EIA
www.eia.gov › tools › faqs › faq
Nov 4, 2021 · "The U.S. Energy Information Administration (EIA) estimates that electricity transmission and distribution (T&D) losses equaled about 5% of ..."
coal_power_plant.efficiency
33%
How much of the coal's heat energy becomes electricity
Transformative Power Systems | Department of Energy
https://www.energy.gov/fecm/transformative-power-systems
car.fuel_economy
25.4 miles per gallon gasoline
Gas mileage of an average American new car
This datapoint is conformable with [electric_car.efficiency], because the calculator understands 'gallon gasoline' as an energy unit.
Citation:
"The average fuel economy for new 2020 model year cars, light trucks and SUVs in the United States was 25.4 miles per US gallon (9.3 L/100 km)."
- Fuel economy in automobiles - Wikipedia
electric_car.efficiency * li_ion.charge_discharge_efficiency * (100% - power_grid.losses) * coal_power_plant.efficiency
car.fuel_economy
fuel_economy_if_coal
(calculation loading)
For natural gas power plants:
Some have the same efficiency as coal power plants (33%). Results would be about the same as above. (...)( Although in theory, coal and natural gas have different GHG emissions per unit energy(...)( which we didn't factor in, and maybe we should for best precision ) - in practice, they're about the same, due to natural gas#fugitive emissions. Both are close enough to gasoline, for the purpose of the calculations on this page. )
Other natural gas power plants (the more advanced "combined-cycle" type) are more efficient: up to 60%:
natural_gas_combined_cycle_power_plant.efficiency
60%
How much of the natural gas's heat energy becomes electricity, in an advanced "combined cycle" power plant
This is considered a "maximum" value - the best natural gas power plants achieve this.
Simpler/older natural gas plants (no combined cycle) have only an efficiency of 33%, same as [coal_power_plant.efficiency].
Read more: https://energyeducation.ca/encyclopedia/Natural_gas_power_plant
electric_car.efficiency * li_ion.charge_discharge_efficiency * (100% - power_grid.losses) * natural_gas_combined_cycle_power_plant.efficiency
car.fuel_economy
fuel_economy_if_advanced_natural_gas
(calculation loading)
ev.battery
65.2 kWh
Energy capacity of the average electric vehicle battery
Useable battery capacity of full electric vehicles
https://ev-database.org/cheatsheet/useable-battery-capacity-electric-car
li_ion.ghg_by_energy
73 kg / kWh
Greenhouse gas emissions (CO2eq) of producing a lithium-ion battery
"by energy" here means "by the size of the battery, defined by how much energy can be stored".
What is the environmental impact of lithium batteries? - Changeit ...
changeit.app › blog › 2021-03-26-environmental-impact-of-lithium-batteries
coal.ghg_by_energy
95.35 kg / million btu
CO2 emissions of burning coal
https://www.eia.gov/environment/emissions/co2_vol_mass.php
gasoline.ghg_by_energy
71.30 kg / million btu
CO2 emissions of burning gasoline
https://www.eia.gov/environment/emissions/co2_vol_mass.php
usa.natural_gas.fugitive_ghg
176.1 million tonnes / year
Greenhouse gas CO2eq of fugitive methane leaks from all natural gas infrastructure in the USA
Environmental Protection Agency (EPA)
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
2016 Complete Report (PDF)
Using data from 2014
usa.natural_gas.energy
27.9 quadrillion btu / year
U.S. energy consumption from natural gas combustion only
Environmental Protection Agency (EPA)
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
2016 Complete Report (PDF)
Datapoint was found on page 115, from pie chart and line graph, using data from 2014
natural_gas.fugitive_ghg_by_energy
usa.natural_gas.fugitive_ghg / usa.natural_gas.energy
Fugitive emissions (CO2eq) of natural gas, per unit energy
Average based on US datapoints.
natural_gas.ghg_by_energy
53.07 kg / million btu
CO2 emissions of burning natural gas
Does not include the fugitive methane emissions from unburned fuel. Those vary by how the gas is burned.
https://www.eia.gov/environment/emissions/co2_vol_mass.php
ev.lifespan
8 years
Expected lifespan of an electric vehicle
Batteries usually are the component that wears out first.
average_us_vehicle.mileage_by_time
32 miles/day
Distance driven by the average American vehicle
Top Numbers Driving America's Gasoline Demand
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand
car.fuel_economy
25.4 miles per gallon gasoline
Gas mileage of an average American new car
This datapoint is conformable with [electric_car.efficiency], because the calculator understands 'gallon gasoline' as an energy unit.
Citation:
"The average fuel economy for new 2020 model year cars, light trucks and SUVs in the United States was 25.4 miles per US gallon (9.3 L/100 km)."
- Fuel economy in automobiles - Wikipedia
So far, we still haven't counted the environmental impact of making an electric car, which is significantly more than for a gasoline-powered car:
For simplicity sake, we're just going to count the emissions of making the batteries, and assume that making the rest of the car would take roughly the same emissions as making a gasoline-powered vehicle: (...)( Technically, the assumption is that the emissions divided by lifespan are about the same. Gasoline vehicles are more complex than batteryless EVs, but also have a longer lifespan. ):
Estimate for lithium-ion electric cars:
ev.battery * li_ion.ghg_by_energy / ev.lifespan
tonnes / year
battery_ghg
(calculation loading)
Now compare for the gasoline a non-electric car would burn, on average:
gasoline.ghg_by_energy * average_us_vehicle.mileage_by_time / car.fuel_economy
tonnes / year
gasoline_ghg
(calculation loading)
Now, for coal power plants charging EVs, same amount of driving:
coal.ghg_by_energy * average_us_vehicle.mileage_by_time / fuel_economy_if_coal
tonnes / year
coal_ghg
(calculation loading)
Now, for advanced natural gas power plants charging EVs, same amount of driving:
(natural_gas.ghg_by_energy + natural_gas.fugitive_ghg_by_energy) * average_us_vehicle.mileage_by_time / fuel_economy_if_advanced_natural_gas
tonnes / year
advanced_natural_gas_ghg
(calculation loading)
Add the battery emissions:
battery_ghg + coal_ghg
tonnes / year
total_ghg_if_coal
(calculation loading)
battery_ghg + advanced_natural_gas_ghg
tonnes / year
total_ghg_if_advanced_natural_gas
(calculation loading)
Now, for the final comparison:
total_ghg_if_coal
% gasoline_ghg
(calculation loading)
total_ghg_if_advanced_natural_gas
% gasoline_ghg
(calculation loading)
Thus, with coal power, emissions are worse than driving a gasoline-powered car. But for advanced natural gas power plants, emissions are about half. In either case, this doesn't count the other environmental impacts (non-CO2) of mining lithium & cobalt.
Maybe there would be a good case for fossil-fuel-electricity-powered vehicles if carbon capture and storage could be fully & safely applied to the power plants.