View source for Archive:000/Electric vehicles/Fossil fuel powered

If you charge an [[electric vehicles|electric car]] with electricity that was generated by [[fossil fuels]], is it '''as bad''' for the environment as driving a gas car?

==Short answer==
<big>'''Yes.'''</big>

The carbon emissions, compared to a gasoline car, are approximately:
* 135% for coal power plants
* 89% for ''older'' natural gas power plants {{light|(more common)}}
* 56% for ''newer'' natural gas power plants {{light|(less common)}}

==Long answer==

The following calculations compare the average gasoline-powered vehicle with the average [[lithium-ion battery]]-based electric vehicle. Greenhouse gas emissions are in tonnes CO<sub>2</sub> equivalent (CO2eq):

<!-- TODO: add a popup box for assumptions:
* no jevons paradox
* battery is the main difference in production emissions (EV as compared to gas car) (amortized over lifespan)
-->

'''Usage emissions''' <!-- not technically a heading. we don't want mediawiki to generate a table of contents. -->

{{dp
|<nowiki>electric_car.fuel_economy_equivalent</nowiki>
|<nowiki>100 miles per 34.6 kWh</nowiki>
|<nowiki>The "gas mileage" equivalent for an average electric car.</nowiki>
|<nowiki>Average Electric Car kWh Per Mile [Results From 231 EVs]</nowiki><br /><nowiki>
ecocostsavings.com › average-electric-car-kwh-per-mile </nowiki>
}}
{{dp
|<nowiki>li_ion.charge_discharge_efficiency</nowiki>
|<nowiki>85%</nowiki>
|<nowiki>When you charge a lithium-ion battery, this much of the energy can be recovered. The rest is lost as heat.</nowiki>
|<nowiki>Range: 80 to 90 %</nowiki><br /><nowiki>
from wikipedia; haven't found original source yet</nowiki>
}}
{{dp
|<nowiki>power_grid.losses</nowiki>
|<nowiki>5%</nowiki>
|<nowiki>Electricity lost in transmission & distribution</nowiki>
|<nowiki>Frequently Asked Questions (FAQs) - U.S. Energy Information ... - EIA</nowiki><br /><nowiki>
www.eia.gov › tools › faqs › faq</nowiki><br /><nowiki>
Nov 4, 2021 · "The U.S. Energy Information Administration (EIA) estimates that electricity transmission and distribution (T&D) losses equaled about 5% of ..."</nowiki>
}}
{{dp
|<nowiki>coal_power_plant.efficiency</nowiki>
|<nowiki>33%</nowiki>
|<nowiki>How much of the coal's combustion heat energy becomes electricity</nowiki>
|<nowiki>Transformative Power Systems | Department of Energy</nowiki><br /><nowiki>
https://www.energy.gov/fecm/transformative-power-systems</nowiki>
}}
{{dp
|natural_gas_power_plant.efficiency
|33%
|How much of the gas combustion heat becomes electricity
|This stat is for simple (older tech) natural gas power plants. The efficiency is the same as for coal and nuclear power. The process is the same: Heat boils water, creates steam to drive a turbine.
}}
{{dp
|<nowiki>car.fuel_economy</nowiki>
|<nowiki>25.4 miles per gallon gasoline</nowiki>
|<nowiki>Gas mileage of an average American new car</nowiki>
|<nowiki>This datapoint is conformable with [electric_car.fuel_economy_equivalent], because the calculator understands 'gallon gasoline' as an energy unit.</nowiki><br /><nowiki>
</nowiki><br /><nowiki>
Citation:</nowiki><br /><nowiki>
"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)."</nowiki><br /><nowiki>
- Fuel economy in automobiles - Wikipedia</nowiki>
}}
{{dp
|<nowiki>coal.ghg_by_energy</nowiki>
|<nowiki>95.35 kg / million btu</nowiki>
|<nowiki>CO2 emissions of burning coal</nowiki>
|<nowiki>https://www.eia.gov/environment/emissions/co2_vol_mass.php</nowiki>
}}
{{dp
|<nowiki>gasoline.ghg_by_energy</nowiki>
|<nowiki>71.30 kg / million btu</nowiki>
|<nowiki>CO2 emissions of burning gasoline</nowiki>
|<nowiki>https://www.eia.gov/environment/emissions/co2_vol_mass.php</nowiki>
}}
{{dp
|<nowiki>usa.natural_gas.fugitive_ghg</nowiki>
|<nowiki>176.1 million tonnes / year</nowiki>
|<nowiki>Greenhouse gas CO2eq of fugitive methane leaks from all natural gas infrastructure in the USA</nowiki>
|<nowiki>Environmental Protection Agency (EPA)</nowiki><br /><nowiki>
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014</nowiki><br /><nowiki>
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014</nowiki><br /><nowiki>
2016 Complete Report (PDF)</nowiki><br /><nowiki>
Using data from 2014</nowiki>
}}
{{dp
|<nowiki>usa.natural_gas.energy</nowiki>
|<nowiki>27.9 quadrillion btu / year</nowiki>
|<nowiki>U.S. energy consumption from natural gas combustion only</nowiki>
|<nowiki>Environmental Protection Agency (EPA)</nowiki><br /><nowiki>
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014</nowiki><br /><nowiki>
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014</nowiki><br /><nowiki>
2016 Complete Report (PDF)</nowiki><br /><nowiki>
Datapoint was found on page 115, from pie chart and line graph, using data from 2014</nowiki>
}}
{{dp
|<nowiki>natural_gas.fugitive_ghg_by_energy</nowiki>
|<nowiki>usa.natural_gas.fugitive_ghg / usa.natural_gas.energy</nowiki>
|<nowiki>Fugitive emissions (CO2eq) of natural gas, per unit energy</nowiki>
|<nowiki>Average based on US datapoints.</nowiki>
}}
{{dp
|<nowiki>natural_gas.ghg_by_energy</nowiki>
|<nowiki>53.07 kg / million btu</nowiki>
|<nowiki>CO2 emissions of burning natural gas</nowiki>
|<nowiki>Does not include the fugitive methane emissions from unburned fuel. Those vary by how the gas is burned.</nowiki><br /><nowiki>
</nowiki><br /><nowiki>
https://www.eia.gov/environment/emissions/co2_vol_mass.php</nowiki>
}}
{{dp
|<nowiki>ev.lifespan</nowiki>
|<nowiki>8 years</nowiki>
|<nowiki>Expected lifespan of an electric vehicle</nowiki>
|<nowiki>Batteries usually are the component that wears out first.</nowiki>
}}
{{dp
|<nowiki>average_us_vehicle.mileage_by_time</nowiki>
|<nowiki>32 miles/day</nowiki>
|<nowiki>Distance driven by the average American vehicle</nowiki>
|<nowiki>Top Numbers Driving America's Gasoline Demand</nowiki><br /><nowiki>
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand</nowiki>
}}
{{dp
|<nowiki>natural_gas_combined_cycle_power_plant.efficiency</nowiki>
|<nowiki>60%</nowiki>
|<nowiki>How much of the natural gas's heat energy becomes electricity, in an advanced "combined cycle" power plant</nowiki>
|<nowiki>This is considered a "maximum" value - the best natural gas power plants achieve this.</nowiki><br /><nowiki>
Simpler/older natural gas plants (no combined cycle) have only an efficiency of 33%, same as [coal_power_plant.efficiency].</nowiki><br /><nowiki>
</nowiki><br /><nowiki>
Read more: https://energyeducation.ca/encyclopedia/Natural_gas_power_plant</nowiki>
}}

''For a gasoline car'' {{light|(typical usage)}}:
{{calc
|average_us_vehicle.mileage_by_time / car.fuel_economy * gasoline.ghg_by_energy
|tonnes/year
|usage_emissions_if_gasoline_car
}}


''For an EV charged by '''coal''' power plants'' {{light|(same amount of driving as above)}}:
{{calc
|average_us_vehicle.mileage_by_time / electric_car.fuel_economy_equivalent * coal.ghg_by_energy / coal_power_plant.efficiency / (100% - power_grid.losses) / li_ion.charge_discharge_efficiency 
|tonnes/year
|usage_emissions_if_EV_coal
}}


''For an EV charged by '''natural gas''' power plants'' {{light|(same amount of driving)}}:
{{calc
|average_us_vehicle.mileage_by_time / electric_car.fuel_economy_equivalent * (natural_gas.ghg_by_energy + natural_gas.fugitive_ghg_by_energy) / natural_gas_power_plant.efficiency / (100% - power_grid.losses) / li_ion.charge_discharge_efficiency
|tonnes/year
|usage_emissions_if_EV_natural_gas
}}


''For an EV charged by advanced {{light|(combined-cycle type)}} natural gas power plants'' {{light|(same amount of driving)}}:
{{calc
|average_us_vehicle.mileage_by_time / electric_car.fuel_economy_equivalent * (natural_gas.ghg_by_energy + natural_gas.fugitive_ghg_by_energy) / natural_gas_combined_cycle_power_plant.efficiency / (100% - power_grid.losses) / li_ion.charge_discharge_efficiency
|tonnes/year
|usage_emissions_if_EV_advanced_natural_gas
}}


'''Battery production emissions''' <!-- not technically a heading. we don't want mediawiki to generate a table of contents. -->

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, let's assume that ''batteries'' account for the entire difference between electric cars and gasoline cars, in terms of GHG emissions of ''production'' divided by vehicle ''lifespan''. {{x|A gasoline vehicle is a bit more complex than a batteryless EV, but the former also has a longer lifespan.}}

{{dp
|<nowiki>ev.battery</nowiki>
|<nowiki>65.2 kWh</nowiki>
|<nowiki>Energy capacity of the average electric vehicle battery</nowiki>
|<nowiki>Useable battery capacity of full electric vehicles</nowiki><br /><nowiki>
https://ev-database.org/cheatsheet/useable-battery-capacity-electric-car</nowiki><br /><nowiki>
</nowiki>
}}
{{dp
|<nowiki>li_ion.ghg_by_energy</nowiki>
|<nowiki>73 kg / kWh</nowiki>
|<nowiki>Greenhouse gas emissions (CO2eq) of producing a lithium-ion battery</nowiki>
|<nowiki>"by energy" here means "by the size of the battery, defined by how much energy can be stored".</nowiki><br /><nowiki>
</nowiki><br /><nowiki>
What is the environmental impact of lithium batteries? - Changeit ...</nowiki><br /><nowiki>
changeit.app › blog › 2021-03-26-environmental-impact-of-lithium-batteries </nowiki>
}}
''For battery production:''
{{calc
|ev.battery * li_ion.ghg_by_energy / ev.lifespan
|tonnes/year
|battery_emissions
}}



'''''Now, for the final comparison:'''''
{{calc
|usage_emissions_if_EV_coal + battery_emissions
|% usage_emissions_if_gasoline_car
}}

{{calc
|usage_emissions_if_EV_natural_gas + battery_emissions
|% usage_emissions_if_gasoline_car
}}

{{calc
|usage_emissions_if_EV_advanced_natural_gas + battery_emissions
|% usage_emissions_if_gasoline_car
}}

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 {{light|(non-CO<sub>2</sub>)}} 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.

<!--
 TALK: add scenario where fuel-cell vehicles are powered by hydrogen gas made from fossil fuels?
       or should that go elsewhere?
-->
==See also==
* [[Calc:If all vehicles were electric]]
* [[Public transit]]
* [[Walkability]]