Breakeven between ICE and EV

As an EV owner, I have always been a bit uncertain where the breakeven point is in driving an electric vehicle (EV), as compared to an old car with an internal combustion engine (ICE). I went from a 17 year old Daihatsu Sirion ICE to a new Mini Cooper EV a couple of years ago. While I love the Mini, I was still uncertain whether I should have pushed on and nursed the Sirion along for another couple of years.

I follow a couple of renewable energy/climate change vloggers, and a comment from another watcher on a post by the channel Just Have a Think earlier this year encapsulated my thinking (2024). 

Commenter @crnlbwlawson explained that their "32 years of driving" was in older second-hand ICEs, beginning with a two year old Honda then driven for 16 years, followed by a "10 yr old Ford Escort [driven for a further] 5 years". There are numerous other examples, with the commenter explaining they have "spent less than $10k dollars on vehicles for myself in 32 years of driving. How much carbon dioxide did I save from being produced by not buying new vehicles that had to be created during that time span?" (Just Have a Think, 2024). 

I felt that @crnlbwlawson had raised a valid point. However, while I get the second-hand line - not needing another vehicle to be manufactured - I am not sure that comparing overall purchase spend to emissions is necessarily a valid part of the argument. To follow up on the second-hand line, I ran a search for "is driving old ICE cars better for climate change than new EVs",  and got a few pieces which seemed to evaluate the issues reasonably logically. 

Of "the energy and CO2 a petrol car is responsible for in its lifetime, roughly four times is in the driving compared with the manufacturing. For an EV it’s about three times" and, if we drive a reasonable amount - which I suspect may be around 20,000km annually (Baldwin, 2022) - "Getting an EV would after a very few years move you into credit". The advice was also given to sell older ICE vehicles to people who did very few kms, which also seemed sensible (Horrell, 2022). 

"Despite the bump in CO2 from manufacturing an electric car and its battery, a new EV would start cutting emissions after 20,000-32,000 miles in the UK (32,000-50,000km)". The "average UK driver replacing an 'old banger' would pay off the carbon debt from buying a new EV within around four years, with the exact timelines depending on the fuel efficiency of the car being scrapped, annual mileage and the battery size of the new EV" (Evans, 2023; see also graph accompanying this post).

"According to [...] a model developed by the Argonne National Laboratory in Chicago, [...] an EV’s carbon footprint [...] begins to fall below [an ICE...] vehicle [...] at around 13,500 miles. So after an average year of driving, the EV is better for the environment" (Baldwin, 2022). It should be noted that this breakeven analysis allows for the US grid being 28% coal-powered (Baldwin, 2022). 

It seems that the faster we can move to EV vehicles, the better it will be for our planet.

However, what if the car owner is using renewables - such as photo voltaics (PV) - to recharge the EV battery? Using renewables for charging seems a long way ahead of the ICE carbon footprint. And - luckily - I am in that enviable position as we have enough PV installed at home to cover charging the EV almost all year round. Or PV system has been running for 14 years without a hitch; a well-sunk cost. The remainder of charging energy in winter comes via a grid-tie system, which in the South Island of New Zealand is sourced largely from hydro-power (NZ runs at roughly 84% renewable generation; EM6, 2024), but it should be noted that there is sometimes a small power swapsie overnight from the North Island, where power comes from hydrothermal, wind, AND fossil fuel generation (Transpower, 2024). So not perfect, but pretty good.

While this is not a very scientific analysis, I feel reassured that the EV purchase was a sound decision.

Sam

References:

Baldwin, R. (2022, April 29). New EV vs. old beater: Which is better for the environment?. Ars Technica. https://arstechnica.com/cars/2022/04/new-ev-vs-old-beater-which-is-better-for-the-environment/

EM6. (2024). Electricity Market Overview. https://app.em6.co.nz/

Evans, S. (2024, October 10). Fact Check: 21 Misleading Myths about EVs. CarbonBrief. https://www.carbonbrief.org/factcheck-21-misleading-myths-about-electric-vehicles/

Horrell, P. (2022). Mythbusting the world of EVs: better to buy new or keep your old car?. Top Gear. https://www.topgear.com/car-news/electric/mythbusting-world-evs-better-buy-new-or-keep-your-old-car

Just Have a Think. (2024, April 29). China's Cheating Dragon?. YouTube. https://youtu.be/bmz4nzcsx-4

Transpower. (2024). Today's HVDC Transfer Summary. https://www.transpower.co.nz/system-operator/live-system-and-market-data/consolidated-live-data