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We're Charging Our Cars Wrong

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Re: We're Charging Our Cars Wrong

#191

Post by cyberax »

adrian_b wrote: post #162
mschuster91 wrote: post #143

Earlier quoted context omitted.

Modern petrol pumps have break-away detection, it can recognize when the nozzle/hose is broken along the chain - I _think_ it works via the nozzle being lower gauge, which means when the flow rate suddenly increases there must be a high volume leak in the hose. And even then, it's only a few liters a minute. That's enough for a nasty fire, yes, but you can usually extinguish it with a handheld extinguisher. Cars, at…

There is really no difference between the two cases, because any EV chargers will also have multiple levels of over-current, over-voltage and short-circuit protection, i.e. both at each charger and for the entire charging station. So not even an exploding car would be able to prevent the disconnection of the chargers by some of the protection circuits.

The issue here is that interrupting a 7.2kV 50A current is not easy. If an arc ignites, it can keep the current flowing for quite a while. Long enough to kill anybody unlucky enough to be a part of the ground fault path.

Re: We're Charging Our Cars Wrong

#192

Post by loeg »

coryrc wrote: post #182
loeg wrote: post #99

Earlier quoted context omitted.

The 7mph claim is inflated. The rare EV gets more than 5 mi/kWh in any situation, especially highway driving, and your L1 charging is getting you roughly 1 kWh/hr. > The average car is driving 60 minutes per day This is a sleight of hand. Non-average situations arise all the time. Your proposal is ridiculously burdensome and not especially helpful.

> Non-average situations arise all the time. Of course. We already have blanketed the country with level 3 charging. You can reach 99% of the country solely using Tesla Superchargers. The non-average problem is solved. What we need to solve is the "can renters buy EVs knowing they will always have reasonably-priced place to charge" problem.

I think the authors of the article would opine that we don't have nearly enough DC fast-charging, actually (and I would agree).

Re: We're Charging Our Cars Wrong

#193

Post by loeg »

ac29 wrote: post #178
loeg wrote: post #99

Earlier quoted context omitted.

The 7mph claim is inflated. The rare EV gets more than 5 mi/kWh in any situation, especially highway driving, and your L1 charging is getting you roughly 1 kWh/hr. > The average car is driving 60 minutes per day This is a sleight of hand. Non-average situations arise all the time. Your proposal is ridiculously burdensome and not especially helpful.

>your L1 charging is getting you roughly 1 kWh/hr 12 and 16A L1 chargers are common which is 1.44 and 1.92kW respectively at 120V. Its not 100% efficient but they definitely deliver more than 1kW to the battery.

12A L1 doesn't actually deliver much more than 1 kW in practice. Closer to 1.0 than 1.4.

Re: We're Charging Our Cars Wrong

#194

Post by loeg »

rswail wrote: post #108
loeg wrote: post #103

Earlier quoted context omitted.

How is that useful for this analysis? I agree it might be interesting in the abstract, and probably interesting for an investor choosing how to deploy capital. But I don't think it has any impact on the argument. Clearly there is a high cost to deploying existing charging stalls. Lowering that cost would clearly increase infrastructure rollout.

Part of the article is claiming that the rollout of EV charging is slowed by the large capital cost, and about how to reduce that capital cost. But without comparing to existing ICE refuelling, which is what EV charging replaces/stands alongside, there's no real identification as to whether the capital costs actually are slowing the rollout. What is driving the rollout is demand not supply . Of course, they're relate…

> But without comparing to existing ICE refuelling, which is what EV charging replaces/stands alongside, there's no real identification as to whether the capital costs actually are slowing the rollout.

I'm still not following here. Again, it just does not seem relevant.

> What is driving the rollout is demand not supply.

Uh, sure, but at lower capital cost there is some marginal demand worth pursuing. And lower prices to the consumer would stimulate higher demand.

Re: We're Charging Our Cars Wrong

#195

Post by loeg »

stavros wrote: post #133
loeg wrote: post #99

Earlier quoted context omitted.

The 7mph claim is inflated. The rare EV gets more than 5 mi/kWh in any situation, especially highway driving, and your L1 charging is getting you roughly 1 kWh/hr. > The average car is driving 60 minutes per day This is a sleight of hand. Non-average situations arise all the time. Your proposal is ridiculously burdensome and not especially helpful.

Owning an EV, I can confirm your numbers. I'm in a 240V country, but level 1 is still pretty slow. It's great for the home, but I'd want at least 3-phase AC charging when I'm out.

Yeah, FWIW I also have an EV, get ~2.2 mi/kWh highway and ~3 around town, and L1 charging on 120V gets me, you know, 1.0-1.1 kW.

Re: We're Charging Our Cars Wrong

#196

Post by insane_dreamer »

IneffablePigeon wrote: post #120
monero-xmr wrote: post #118

Earlier quoted context omitted.

Where I live the electricity is primarily generated by fossil fuels. The light is weak for many months of the year, and wind power is apparently way too expensive if they remove the subsidies (weird!). Wouldn’t gas cars just eliminate the middleman of fossil fuels -> power plant -> car? Like we did before EVs? I would love nuclear power but it doesn’t appear to be happening

EVs emit less carbon even when powered by a fossil fuel dominated grid. The power plant is more efficient than your car, and often uses LNG rather than petrol or diesel, and there are still some renewables in almost any grid. In addition, air pollution close to where you live will be lower. In addition, the grid can be decarbonised over time and your car will become greener as it does.

Do you know whether the transmission costs of electricity are higher than that of transporting gas or lng, and whether that's a factor here?

Re: We're Charging Our Cars Wrong

#197

Post by insane_dreamer »

monero-xmr wrote: post #121
IneffablePigeon wrote: post #120

Earlier quoted context omitted.

EVs emit less carbon even when powered by a fossil fuel dominated grid. The power plant is more efficient than your car, and often uses LNG rather than petrol or diesel, and there are still some renewables in almost any grid. In addition, air pollution close to where you live will be lower. In addition, the grid can be decarbonised over time and your car will become greener as it does.

The convenience to me of being able to refuel anywhere quickly, plus the dubious carbon savings, plus the immediate discount on the car purchase (without any subsidies), makes it a moral purchase rather than a practical one. I am not very impressed by the benefits. I like how EVs accelerate faster. Otherwise it would make my life way more inconvenient, which I surmise is a major blocker for most potential EV purchase…

Being able to charge nightly (when needed) at home has been a game changer for us. No more waiting in line at Costco or "we need to fill up the car before X". Car is always fully charged.

Plus for us at least, because we have a very low KwH _night_ rate, our EV is 10x cheaper to run than our ICE. It's a significant difference.

And that's not counting the environmental concerns.

Multi-day trips are another story. But we take very few of those.

Re: We're Charging Our Cars Wrong

#198

Post by kelnos »

nothercastle wrote: post #173
theshrike79 wrote: post #164

Earlier quoted context omitted.

Electric engines are 90-95 efficient in converting power to motion. Even the very best experimental gasoline engines in Toyota's labs are around 30-35% efficient. Even if all gasoline and diesel was used in massive generator units to produce electricity, EVs would still be better for the environment and the total gasoline/diesel usage would go down.

But the power plant has only slightly higher efficiency off the fossil fuels it burns. So you need to use the ev to store excess grid solar generated during the day to truly get an advantage

At least the power plant is burning that fuel and spewing garbage into the air in a place that isn't your home. And power plants capture more of that pollution than cars do, not to mention that many of them burn cleaner fuel than gasoline or diesel.

And most people tend to keep their cars for 10+ years. The power grid is changing all the time, and it's likely in the time that you own your EV, the sources it gets powered from will become cleaner.

Re: We're Charging Our Cars Wrong

#199

Post by [deleted] »

brabel wrote: post #112
cyberax wrote: post #64

Earlier quoted context omitted.

Imagine a catastrophic fault: a dude in another car drives into your car, and a conductor in the car breaks off and energizes the car body. The current now goes through the car body into the ground, and also through the grounding wire back to the charger (EVSE). It's a phase-to-ground short. The charger tries to interrupt the flow, but the short circuit fries the power electrics in the buck converter (MOSFET/IGBTs ca…

Imagine a catastrophic fault: a dude in another car drives into your car at the petrol pump. The petrol pump starts dropping huge amounts of petrol on the ground. Part of the car wreck falls back on the ground and ignites a fire, causing the whole station to blow up, killing everyone within 100 meters. Clearly, we cannot allow petrol stations to exist.

[deleted]

Re: We're Charging Our Cars Wrong

#200

Post by kkfx »

To reduce public infra cost we simply need to ERASE the speculation around it. Simply only grid operators are allowed to install chargers and them are allowed to be payed only with a bank card not with apps not with dedicated cards and so on.

Cutting this part will makes the very same hw much cheaper.

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