There are many articles on the internet and mainstream media which claim that EV's are not as 'zero emission' as they claim. Many are unsupported by facts or the facts being used are inappropriate (comparing a sub-compact hatch petrol with a large Sedan) or out of date (reports on grid carbon for years before).
With that in mind, I have been looking into the actual facts around the claims that EV's are not 'that' green.
Let's start with one fact that I am not disputing. The energy used to power my EV comes 100% from the National Grid, that grid is far from carbon neutral. So, there are emissions associated with the running of the EV. What are they though and how do they compare to those of an ICE powered vehicle? Having worked that through i'll then look at the hidden emissions associated with the non-EV energy source. The emissions that the 'Big Oil' companies don't want you to think about.
For the purposes of this comparison I am going to look at the nearest ICE sister to the Jaguar I-Pace. That would either be the larger F-Pace or the smaller E-Pace. To avoid any misrepresentation of fact, let's use the smaller, more economical E-Pace. While we're at it, let's use the middle of the range 200 bhp 2.0 Litre Petrol. So we're comparing a mid-sized SUV from Jaguar with a (slightly larger and definitely more powerful) mid-sized SUV from Jaguar.
According the the .gov figures for the E-Pace. It has an emissions rating of 186g CO2/km (296g CO2/mile) and a combined mpg figure of 27.8 mpg.
We know that the I-Pace has a (tailpipe) emissions rating of ZERO CO2/km and an average consumption of 419 Wh/Mile ( https://www.ipace.online/post/the-second-month-october-2019 ).
Luckily, the national grid provides their CO2 rating for any given period via the Grid Carbon app.
At time of writing, a dull, wet but not very windy November day, the average was approx 250gCO2/kWh over a 24 hour period with around 40% coming from Gas and only 4.5% from coal. According to a recent report from Nation Grid ESO, there are around 2% transmission losses in the grid. There is also a small loss of energy in the conversion from AC to DC at the vehicle so 1kWh generated at the power station equals around 950Wh into the vehicle. This might seem trivial but you'll see why I mention it later. So, that 250gCO2/kWh generated actual equates to 263gCO2/kWh that gets into the I-Pace. Meaning that there's (263/0.419) 110gCO2/mile.
296gCO2/mile for the E-Pace. 110gCO2/mile for the I-Pace. Or, 63% less. NOT Zero but 63% less. For a smaller, less powerful SUV. On a cloudy, rainy day in late Autumn when the grid is quite dirty.
Now, we have resolved the argument that EV's are not as green as the 'Zero Emission' banner might say. Or have we? What we haven't done is taken into account any emissions from the acquisition of the source materials for the Electricity production. Remembering that, at time of writing, almost 50% of the grid was from fossil sources like gas and coal. If we had the information we could add that into the mix, but wait, we haven't compared Apples with Apples. We haven't yet considered the CO2 emissions of the production and transport of the petrol to the car. We have for Electricity but not for the Petrol.
Doing that is hard. There are many more steps in the chain. The petrol forecourt that uses Electric pumps to transfer the fuel from storage tank to car. Their canopy and shop lights and heating that us EV drivers don't benefit from (yet/mainly). Then there's the transport emissions. Just getting the fuel from the refinery to the forecourt, by road, using Diesel trucks. Then, there's the vast amounts of energy that go into refining the Crude Oil into Petrol. What is the impact of that.?
I can tell you. Thanks mainly to the huge carrying capacity of most tankers (around 38,000 litres) the impact of using a truck that will struggle to better 5mpg is only around 2gCO2/mile of fuel it delivers to the forecourt for the E-Pace to use.
Not really worth considering but ironically around the same as the losses, in percentage terms, in the National grid and AC/DC conversion. (I told you i'd come back to that).
What would be really useful to know is the CO2 emissions of the Oil Refinery for every gallon of Petrol produced.
Just in consumed energy the Fawley Refinery (largest in the UK) uses 1700MWh of fuel*. It uses its own furnaces to burn oil to create to steam and electricity. That's a much dirtier power source than pulling 1700MWh from the grid but if they did then that would mean a CO2 figure (250*1700*1000) of 425Million gCO2/h. They produce 800,000 tonnes of petrochem per year which equals 1.1Million Litres per year or 240,398 Gallons. So for every Gallon of petrol produced, IF they pulled their energy from the 50/50 dirty/Clean grid, would produce 1.7KgCO2. Which means our E-Pace driving a mile would need to account for another 63gCO2/mile on top of the 296gCO2/mile from the tailpipe.
What we don't know is the actual emissions from the Fawley Refinery Furnaces but we can assume that as they are fuelled by oil, they are more CO2 per kWh than the current National Grid which uses a mix of Oil, Gas, Coal and renewable sources.
That also doesn't take into account ANY of the emissions from the refining process itself. That's just the power to create heat and electricity for the plant.
Remember that this flare, the thing we all recognise as identifying a refinery, is when unburnt hydrocarbons are being released by the refinery to prevent unsafe gas build-up**. Those emissions are not recorded or form part of the calculation above.
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