Doesn’t the electricity generation produce CO2? So what’s the point of an EV?

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This is just going to be a quick note to answer this question as it is often asked of me by the doubters.

The answer is that electricity generation does produce carbon dioxide, but there are three factors that mean this is much less for an EV than the equivalent fossil fuel car.

1) The electricity is produced by a mix of generating methods, some such as coal produce a lot of CO2, as do oil and gas fired power stations, but others such as nuclear and especially wind, solar or hydro produce very little. As the UK’s energy mix gradually moves toward these cleaner forms of generation the amount of CO2 an EV generates at the power station becomes less.

2) A power station is much more efficient than the engine in a fossil fuel car. Approximately 20% efficiency is typical for most engines, whereas 33-60% efficiency can be achieved by a coal or gas power station. The efficiency of an EV at turning this electricity into movement is 90%.

3) There is a huge energy and CO2 cost in the drilling for, shipping, refining and delivery of fossil fuel to the point of use where it is burned in a car. Even if you subtract the energy/CO2 required to drill, ship and refine fossil fuel for use in a power station, you are still left with the cost of transportation of the fuel to the petrol station forecourt and the cost of providing and running that forecourt. No such cost exists for the 240v plug in your garage and the cost for public chargers is 10-20 times less than for petrol stations.

As such the well-to-wheel cost and CO2 production for an EV is considerably less as the table below shows.

Emissions and Fuel Cost for a 100-Mile Trip
Vehicle
(compact sedans)
Greenhouse Gas Emissions
(pounds of CO2 equivalent)
Total Fuel Cost
(U.S. Dollars)
Conventional 87 lb CO2 $8.33
Hybrid Electric 57 lb CO2 $5.48
Plug-in Hybrid Electric 62 lb CO2 $5.43
All-Electric 54 lb CO2 $3.74
Source: http://www.afdc.energy.gov/vehicles/electric_emissions.php

So EV’s alone without zero-CO2 electricity cannot save the planet, at present in the UK they are about 62% better at saving the planet than a fossil fuel car.

However if you charge your EV from your solar panels or wind turbine then you really do not have to take this line of questioning lying down.

 

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