Calc:If all vehicles were electric

Suppose we keep the status quo of transportation, but make all vehicles electric. This raises some basic questions:

• How much electricity would we need to power all the vehicles?
• How much energy would it take to manufacture vehicles - both in the short term and long term?
• Which critical minerals would we need, and how much of each?
• Could the minerals be recycled from vehicles at their end-of-life?

Powering the vehicles

Electric cars are more energy-efficient than gas cars, but use a different type of energy, so this might seem like "comparing apples to oranges". But still we can use this fact to help make an estimate. Let's start by establishing a simple ratio:

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

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 / car.fuel_economy ratio (calculation loading)

This tells us that the average electric car has about 4 times the "energy mileage" of the average gas car. But that's without considering the losses in charging and discharging the battery.

Suppose the electric vehicle uses lithium-ion batteries:

li_ion.charge_discharge_efficiency

85%

When you charge a lithium-ion battery, this much of the energy is stored. The rest is lost as heat.

Range: 80 to 90 %
from wikipedia; haven't found original source yet

ratio * li_ion.charge_discharge_efficiency ratio_for_li_ion_vehicles (calculation loading)

Or suppose the electric vehicle uses hydrogen fuel cells:

electrolysis.efficiency

80%

Energy efficiency of producing hydrogen & oxygen gases from water

Hydrogen made by the electrolysis of water is now cost-competitive ...
www.carboncommentary.com › blog › hydrogen-made-by-the-electrolysis...

hydrogen_fuel_cell.efficiency

50%

Electric energy efficiency of an average hydrogen fuel cell

Hydrogen Fuel Cells Fact Sheet
www.californiahydrogen.org › uploads › files › doe_fuelcell_factsheet

ratio * hydrogen_fuel_cell.efficiency * electrolysis.efficiency ratio_for_fuel_cell_vehicles (calculation loading) In this second case, we need electricity to make hydrogen gas, which is later used in the fuel cell to power the car. Hence we consider the losses involved in both processes.

For comparison, consider a car with an internal combustion engine that runs on hydrogen gas instead of gasoline: If the engine's efficiency is similar to a gas car, we end up with something with less overall efficiency than a gas car, because we still have to deal with all the energy losses from making the hydrogen gas in the first place: electrolysis.efficiency ratio_for_hydrogen_combustion_vehicles (calculation loading) This ratio would be less bad if hydrogen combustion engines are more efficient than gasoline combustion engines. More research is needed - you can join the discussion.

So far we've looked at cars - but what about buses, trucks, planes, ships, etc? So far, there isn't a lot of data available. So for these next estimates, we just have to assume that the ratios are similar enough.

We do have data on how much energy the world currently uses for transportation (which we could also break into subcategories, but we won't right now, for simplicity sake). So if we apply the ratios from above:

transport.energy

2890.90 Mtoe/year

Transporation's energy usage - worldwide total

Includes passenger and freight/cargo.

"Key World Energy Statistics 2020" IEA
Page 47 - Simplified energy balance table - World energy balance, 2018

transport.energy / ratio_for_li_ion_vehicles terawatts (calculation loading) transport.energy / ratio_for_fuel_cell_vehicles terawatts (calculation loading) transport.energy / ratio_for_hydrogen_combustion_vehicles terawatts (calculation loading) These wattage ratings would be power averaged over time. Peak power could be higher, but hopefully we'd find ways to smooth that out.

And there we have a simple estimate of how much electricity we would need if all vehicles ran without fossil fuels.

But we're not done, because we also need energy to manufacture the vehicles...