200Wh is about a 20% estimation-factor on top of the commonly claimed 160Wh/km for a tesla. This accounts for any losses from charger to battery. Losses past that point are irrelevant because the point of measurement is battery drain per km. Differences between the test protocol and real world should be mirrored in the econobox stats. Emissions figures were commonly quoted per kWh at the wall socket.
> Not at all. By your (very optimistic) calculations, they are about the same. You'll never pay off the CO2 debt of manufacturing the EV battery, let alone start averting the climate catastrophe!
Precisely my point? I'm asserting that a city-car econobox has better marginal per km emissions than a luxury sports EV. A cayanne will have about 4-6x the emissions as the econobox and that comparison will favour the tesla. Also please do point out where they were optimistic -- there are very few ICEs that get 50g/km?
EV makers play sleight of hand by eliminating the segment of small light cars that can get you two cities over, then claiming their replacement in the form of a luxury performance car is 'better' by comparing it to luxury performance SUVs.
> Not at all. By your (very optimistic) calculations, they are about the same. You'll never pay off the CO2 debt of manufacturing the EV battery, let alone start averting the climate catastrophe!
This isn't as much as you think, most of the industry isn't using NMC anymore and there's less of the expensive materials per cell even compared to earlier LFP variants. If you're not insisting on obscene power densities and range you'll never use then 30kWh of LFP batteries has GHG impact commensurable with a few thousand km of usage of either the econobox or the coal powered luxury EV -- it doesn't take much to tip the balance. Similarly you can use motors without scarce metals.
> Very true. Weird that all of the currently-pushed solutions involve large and expensive EVs that barely do any good.
Because EVs are here to save the car industry not the planet. Although they do have one positive externality: a bunch of people willing to pay $500-1000/kWh allowed for the development of the battery industry where doing it to reduce emissions would have never happened.
Yep, agree with all of that.
>Because EVs are here to save the car industry not the planet.
Especially this.
I've already made the point that EVs are almost like Rai Stones - an immobile indicator of wealth.
That's probably a bit too far. The range issues are very much overblown edge cases. If you're going to make a new personal vehicle it should probably run primarily on a small LFP battery -- whether pure plug in or hybrid.
Modern cars in general are ridiculous, anti-practical conspicuous-consumption symbols of just how much power the owner has to ruin the lives of those around them. EVs are not much different in that regard.
So like a Rai Stone?
>it should probably run primarily on a small LFP battery -- whether pure plug in or hybrid.
If you go down that route, you'll probably work out that people should be riding e-cargo bikes everywhere (I've been tempted myself)
> If you go down that route, you'll probably work out that people should be riding e-cargo bikes everywhere (I've been tempted myself)
They're great. Mine has a solar panel over the cargo bed and never needs charging (literally do not own an AC charger for it). You need some minimal level of concession from driving culture and infrastructure to make them survivable though. They also don't cover all use cases (but carrying the *%#$ full sheet of plywood that is always brought up as somehow being an essential daily staple is quite possible with a variety of designs or trailers).
Interesting - what's your average daily mileage? I'm relatively familiar with the power requirements of EVs, and large-scale solar installations. I have no idea what kind of average charging power a small solar panel provides!
It's a nominal 200W panel (older fairly inefficient monocrystalline, big enough for a small sunshade which is its main function) and will fill the 1.1kWh battery in about a day (in a near-optimal climate), or two if the weather is meh. Before I mounted it on the trike I could get ~100-150km before plugging it into the panel on flatter ground or about 20-30km on a route with several big hills (12% grade) and a heavy (50kg bike + 50-100kg cargo + 75kg rider) load.
The trike is pretty speed limited by handling though (20-25km/h) and it takes very little effort on the flat to keep it above the 25km/h speed limiter. On flat ground or shallow hills (1-2%) during the sunny part of the day (9-3) I can't use more power than the panel provides without going up hills because of the speed restriction.
I'd imagine on a bakfiets in an area where 32km/h limiters were allowed you'd get about 30-50km depending on the terrain.
Some back of the envelope:
Consider this: https://www.bakfiets.com/elektrische-bakfiets/cargobike-clas...
A less ghetto lid than my arrangement would be 0.63m^2
This would fit okay as a lid: https://www.solar4rvs.com.au/sunman-earc-100w-flexible-solar...
a little narrow and would hang over the edge a little.
Assume it's about 45 degrees from optimal (70%) and that you're getting the average irradiance from somewhere like denmark (1000kWh/yr). You'll get about 71kWh/yr. Cut off 7kWh for charging loss so 62kWh.
A typical bike battery is 500Wh, so 120 charges or 1 full charge every 3 days.
A charge might get you 20km or it might get you 90km, but for a typical rider with moderate hills who puts in a 40-60W contribution (same effort as walking) and doesn't want to risk grinding home the last 10km on a cloudy day, a reasonable ballpark is 50km/day. So you're looking at ~15-20km (but you'll need to charge it in winter), or maybe up to 5x that (and decent range even in winter) if you think very carefully about parking, live in a better climate for solar, and do 25 rather than 32.
It's a nominal 200W panel (older fairly inefficient by new standards monocrystalline, big enough for a small sunshade which is its main function) and will fill the 1.1kWh battery in about a day (in a near-optimal climate), or two if the weather is meh. Before I mounted it on the trike I could get ~100-150km before plugging it into the panel on flatter ground or about 20-30km on a route with several big hills (12% grade) and a heavy (50kg bike + 50-100kg cargo + 75kg rider) load.
The trike is pretty speed limited by handling though (20-25km/h) and it takes very little effort on the flat to keep it above the 25km/h speed limiter. On flat ground or shallow hills (1-2%) during the sunny part of the day (9-3) I can't use more power than the panel provides without going up hills because of the speed restriction.
I'd imagine on a bakfiets in an area where 32km/h limiters were allowed you'd get about 30-50km depending on the terrain.
Some back of the envelope:
Consider this: https://www.bakfiets.com/elektrische-bakfiets/cargobike-clas...
A less ghetto lid than my arrangement would be 0.63m^2
This would fit okay as a lid: https://www.solar4rvs.com.au/sunman-earc-100w-flexible-solar...
a little narrow and would hang over the edge a little.
Assume it's about 45 degrees from optimal (70%) and that you're getting the average irradiance from somewhere like denmark (1000kWh/yr). You'll get about 71kWh/yr. Cut off 7kWh for charging loss so 62kWh.
A typical bike battery is 500Wh, so 120 charges or 1 full charge every 3 days.
A charge might get you 20km or it might get you 90km, but for a typical rider with moderate hills who puts in a 40-60W contribution (same effort as walking) and doesn't want to risk grinding home the last 10km on a cloudy day, a reasonable ballpark is 50km/charge. So you're looking at ~15-20km/day (but you'll need to charge it in winter every week or so), or maybe up to 5x that (and decent range even in winter) if you think very carefully about parking, live in a better climate for solar, and do 25 rather than 32.
I'm talking about electrical transmission losses. The worst-case is for high-current, domestic loads, where about 15% of the power from the electrical power generator is lost. Add in another approx. 15% for charging and discharging the EV battery, and it's not so good.
>200Wh/km of wall socket power is about 60MJ per 100km
You forgot the above losses.
>A mostly-ff mix EV starts to look good here.
Not at all. By your (very optimistic) calculations, they are about the same. You'll never pay off the CO2 debt of manufacturing the EV battery, let alone start averting the climate catastrophe!
>Really to reduce emissions quickly in urban or suburban areas we need more vehicles that look like a Zev, an Aptera, suzuki samba, a golf cart or a bicycle etc. and fewer that resemble a tesla or a monster truck (as well as more rail based vehicles).
Very true. Weird that all of the currently-pushed solutions involve large and expensive EVs that barely do any good.