So which car is more environmentally friendly and how do you calculate the CO2 output of an E.V. versus a Petrol car
Here in NZ we are blessed with 4/5ths of our power coming from renewables. Although this has shrunk of late
The balance comes from fossil fuels and is required to maintain the electricity consumption during the year in the North island. Currently the slack is taken up with imported coal, gas and a few other fuels.
The reality is the renewable energy supply cant keep up with demand and anywhere from 40% down to 15% of the more populous North island requires burning fossil fuels to provide us power. Any increase in power over what the clean generation can cope with increases the demand on predominantly coal and gas.
Remember that last sentence as we continue on this train of thought.
CO2 is the apparent villain of burning fossil fuels. We are told to reduce our carbon footprint to save the planet and our leaders have indicated we will no longer be driving petrol cars in the near future and are subsidising purchasing EV’s with tax payer money.
but while your local Greenies are out saving the world one E.V. at a time I decided to sharpen my pencil and do some math.
It is important to note that these calculations don’t include the fact there are far more resources that go into making an E.V. Batteries are costly to manufacture and this in itself causes more CO2. Also they have way more copper and other minerals in them which come from large mines around the globe.
First of all lets take the energy consumption of the average motorist and compare the damage to the environment solely from the energy consumption and ignore the dirty batteries etc that help make E.V’s go.
So let us say the average motorist drives 200 k/m per week which is 10,400 k/m for the year.
For petrol cars (depending on what you drive) you will consume 4 to 12 liters per 100km the higher amount is for your gas guzzler and the lower amount for the efficient car. Lets go half way along at 8 litres per 100 k/m
We can see that the 8 litre per 100km car creates 25,300 grams of CO2 by the time it has completed this distance. If we extrapolate this out over the year we end up with 10,400 k/m by 253 grams of Co2 or 2,631 kilos of CO2.
Plant 93 trees and technically this will give you a zero footprint.
Now lets look at the E.V. Depending on if you have a more economic EV like a Nissan Leaf or a power guzzling Tesla Model x you will consume between 15kw/h to 25kw/h per 100 k/m. from your pockets point of view you are winning but how does this look when you compare this to the power grid?
If you are in the South island you are winning from an enviromental point of view. hydro is powering your E.V. so you can carry on telling everyone you are saving the planet. Just don’t mention the cobalt mining and child labour and you will be fine.
However if you are a North Island E.V. driver then depending on how you try and spin the story, you are of course using more fossil fuel created energy. If we are nice and say that 80% of your power is renewable (oh but it is) but lets be nice and play the game. 20% of the power you consume is generated from fossil fuel. extrapolating out the midway point of 20kw/hour per 100 k over the 10,400 k/m for the year gives us 2.08 gigawatt/h energy consumption for the year. about half will come from coal and half from gas of this 20% which if we look at the graph below gives us ((2.08x1001x0.5) +(2.08X469X0.5)/5
SO this gives you a total of 208 kilos of Co2 from the coal and 98 kilos from the gas or a total of 306 kilos of CO2 your driving is putting into the air. Well done you are way cleaner at only 306 kilo’s of CO2.
But hang on, what did we learn at the beginning? That’s right, any new load adds 100% to the fossil fuel generation because all of the renewable electricity is already being used on the existing load.
This means your lovely little E.V. is spewing out 1,530 kilos or 1 and a half ton’s of Co2 compared to the 2,631 from the petrol car.
So the EV wins again on looking only at the CO2 emissions of powering it. However, The grade of coal used in New Zealand is a lot more polluting than petrol. Exhaust from a petrol car is 13% Co2, 13% water and 73 % Nitrogen. this is pretty clean and if you don’t buy into the alarmism of Co2 then very satisfying. Coal on the other hand spews out sulphur dioxide, nitrogen oxide, coal ash, uranium and thorium, loads of CO2 and even mercury.
What you also need to look at is the difference in manufacturing an E.V. to a petrol car and the long term environmental impact of the two when their parts and ultimately the entire car is laid to rest. Batteries being the biggest one
Feel free to sharpen your pencil and prove my calculations wrong.
I have said it once I will say it again. technology will guide through to better environmental outcomes and all this claim of an urgent fix and not supported by the real world.
Climate scientist seem to only live by their computer models and if they lifted their nose from behind the screen they might notice it is business as normal as far as the climate is concerned.
Power generation, large capacity battery storage and better materials for making batteries will undoubtedly make the EV the car of the future. But as for today its not the shining beacon of environmentally friendliness just yet.