Hacker News Reader

I find the electric car argument not entirely true due to the efficiencies of the electric motor. Producing the power in a plant and then using it on an electric motor is way more efficient than producing the power at the source in an ICE.

Yes, but if we're going to be talking about all-in efficiency, note that a bus or train is significantly more efficient[1] than a single-person vehicle idling in gridlock.

[1] In time, energy, money, infrastructure, maintenance, insurance, human health and life lost to accidents and pollution.

Electric cars don't idle in gridlock, the motors don't consume energy while stopped. They are also more efficient at 10mph than they are at 50mph, let alone 70mph.

> Electric cars don't idle in gridlock

No, but the humans in them do.

Traffic and gridlock waste our time because cars are an incredibly inefficient way to transport people[1].

---

[1] https://humantransit.org/2012/09/the-photo-that-explains-alm...

Also, producing gasoline is not "free". It takes energy to produce and deliver that gasoline to your car.

Numbers I've seen are 5 ~ 8kWh, that's 20-30 miles of electric driving.

Depending on your gasoline car's efficiency and exact kWh number above, the energy to even produce and deliver the gasoline is higher than actually driving an electric vehicle.

No, that isn't how it works at all. You're just measuring it a different point. Power plants have similar thermal efficiency that is compounded by the losses in transmission & charging the battery.

That's exactly how it works. Power plants are not even using the same cycle, it's brayton vs carnot. And power plants have a much higher efficiency overall, often two or more times higher than ICE engines.

https://www.forbes.com/sites/enriquedans/2018/08/19/myths-an...

  Even if the grid were entirely fueled by coal, 31% less energy would be needed to charge EVs than to fuel gasoline cars. If EVs were charged by natural gas, the total energy demand for highway transportation would fall by nearly half. Add in hydropower or other renewables, and the result gets even better, saving up to three-fourths of the energy currently used by gasoline-powered vehicles.

https://yaleclimateconnections.org/2022/08/electrifying-tran...

Untrue. Power plants can be 50-60% efficient (and up to 90% if the waste heat is used for district heating). Meanwhile car ICEs are at best 25-30% efficient (slightly more for diesels). Even with transmission losses of 4-6% and electric car charging/discharging losses of 10-20% the EV comes out ahead even when fired with fossil fuels and saddled with 500 pounds of extra weight.

> losses in transmission & charging the battery

Significantly more losses in the manufacturing, refining, delivering, and distribution of gas.

Huh. Today I learned. https://ui.adsabs.harvard.edu/abs/2020SJRUE..24..669A/abstra...

I always thought the difference was larger for a coal powered electric vehicle.

Can you provide numbers for each of those? ICE thermal efficiency vs Combined Cycle Gas Turbine efficiency, transmission losses per 100 km and expected total, battery roundtrip efficiency, electric motor efficiency?

No, because it's irrelevant. Talking about "electric motor efficiency" is as pointless as talking about the efficiency of the ring and pinion in the axle of vehicle. It isn't where energy is lost.

The total system efficiency is what matters. As other posters mentioned, even diesels beat the efficiency of an EV when you measure well to wheel:

https://ui.adsabs.harvard.edu/abs/2020SJRUE..24..669A/abstra...

The first quote is about mineral resources but the link is about climate and greenhouse gas emissions. I'm sure it was just an oversight, but there is nothing on that EPA page that remotely addresses the mineral resource issue.

"Greening" the world with electric vehicles will first require a significant and rapid increase in our industrial mineral supply. The IEA predicts a 5x increase in required critical metals over the next 17 years to meet clean energy demands and claims "Today, the data shows a looming mismatch between the world’s strengthened climate ambitions and the availability of critical minerals that are essential to realising those ambitions." [1]. Geologists within the industry are publicly claiming that "Global reserves are not large enough to supply enough metals to build the renewable non-fossil fuels industrial system." [2].

But lets just assume we have enough minerals for the sake of argument. How are we actually going to get it out of the ground and into the supply chain fast enough? More mining. More transport. More industry. More pollution. And more fossil fuel consumption in the short term (though as the EPA notes, the long-term emissions balance favors EVs).

If the green energy revolution is going to come true, we're going to require an expansion of mining capacity that the world has literally never seen. I'm not sure everyone advocating green energy understands exactly what's required to make that happen. But the mining industry is certainly aware of the demand! If we give them the green light and an economic incentive, they'll strip mine every mountain in the global south just so everyone in the global north can drive an EV.

[1] https://www.iea.org/reports/the-role-of-critical-minerals-in...

[2] https://tupa.gtk.fi/raportti/arkisto/16_2021.pdf

Electric vehicles are supposed to eventually emit half of the total CO2e compared to ICE vehicles, but importantly that's as calculated over the entire expected lifetime of the compared vehicles. The manufacturing process massively frontloads the EV's emissions such that if you only keep it for ~5 years, you actually end up worse off emissions-wise than if you were driving an economy ICE vehicle. Then there's externalities such as increased damage to roads (asphalt is still a petroleum product), microplastics off tires entering waterways, etc., due to EVs' higher weight.

It makes more sense in almost every case, if you're concerned about emissions, to just buy used whenever possible. This applies across many kinds of products.

Circular economy and cutting excess production are way more effective for mitigating emissions than buying new $SHINY_GADGETs but the nascent cultural default is to buy new because of this or that feel-good ads campaign and/or some kind of stigma around buying things that were previously someone else's.

The car doesn't get scrapped if you only use it for 5 years -- it gets sold on to somebody else.

And if you buy a vehicle used, you're preventing someone else from buying and using that vehicle.

Your argument only really works if you buy a car that was destined for the scrap heap and fix it to make it usable.

Used cars are not supply-constrained. Inventory is declining only because new car supply has been so suppressed over the past couple years, but that doesn't mean they're running out any time soon. So the opportunity cost on the individual level is as I describe: do you reutilize an existing car or do you incarnate (heh) a new one with your market participation? It's true that your new car will likely be someone else's used car, but the argument has a whiff of trickle-down-style economic reasoning that would take more space to unpack.

Further, more demand for used cars would spur the industry to reclaim/refurb salvage titles that were otherwise destined for the scrap heap and sell them on.

We could easily do this wrong, e.g. by shipping busted cars overseas, having them refurbed there, and shipping them back. Or we could do it right and create jobs in America that would stimulate economic activity locally.

This has nothing to do with trickle-down economics - it has everything to do with supply-demand curve.

All cars like this exist on the demand curve - if you don't buy it because you find it undesirable for one reason or another, someone else will. Eventually that falls so far down the curve that it's not worth anyone buying it (no demand) and it either gets scrapped, or it gets exported and someone else uses it outside of the country (which, does happen quite a bit).

Refurbing salvage cars broadly is just not worth it - the time and effort would be better spent make 10-20 new cars, rather than potentially dealing with the liability of a salvage branded car. It's why nobody wants a salvage car.

Used cars aren't supply constrained only at current prices, which are significantly higher than they used to be.

Demand is keeping prices high, there is no lack of demand.

It also ignores that we are slowly, but surely, moving towards more renewables for electricity generation. The UK hardly burns any coal these days, I believe we have 2 coal fired plants that are there mostly for emergencies. Yes, we still produce quite a lot from gas fired plants as they are easy to turn up and down to match demand, but the the direction is set, electricity generation will get greener.

This just feels like a super defeatest post.