What Needs to Happen Before Electric Cars Take Over the World • Hacker News Board

Re: What Needs to Happen Before Electric Cars Take Over the World

#421

Post by pilom » Tue, Dec 19, 2017, 9:19 PM UTC

mikestew wrote: post #375

Retric wrote: post #356

Earlier quoted context omitted.

From a weight perspective they still add range so it's not a bad idea. Further, being able to run some fans or even AC while in full sun is a significant benefit. Car companies are not adding panels because the benefit is not huge, they add complexity and cost, and panels negatively impact styling. Still, you see a lot of campers with solar panels on the roof because a few kwh/day of extra power really does add up ov…

Further, being able to run some fans or even AC while in full sun is a significant benefit. You’re going to need those fans with giant, black heat sinks on your roof. To the point that I wonder if the panels heat the car faster than fans can remove it. Still, you see a lot of campers with solar panels on the roof because a few kwh/day of extra power really does add up over time. You see a solar panel on our VW camper…

I agree with you that the solar panels aren't going to run the motor, but the 660W of solar on my RV with a large battery bank and a 3000W inverter have no trouble running everything in my RV including the AC for an hour here or there (though we did replace the AC with a swamp cooler to be able to run longer in the southwest): http://therecklesschoice.com/2016/04/29/diy-rv-solar/

Re: What Needs to Happen Before Electric Cars Take Over the World

#422

Post by slouch » Tue, Dec 19, 2017, 9:37 PM UTC

RightMillennial wrote: post #361

digi_owl wrote: post #257

Earlier quoted context omitted.

If the range is enough, stopping to charge up for 30 mins means one can also grab a bite to eat. My parents took us kids on car trips during summer holidays, and usually by the time we needed to stop to refuel the car we also took the time to eat and such.

A problem is not everyone wants to wait half an hour for every charge on a long distance trip. If I'm driving 12 hours, I want to get to my destination with minimal interruption. Having to wait 30+ minutes for each of the 2+ refuelings would be a pain and add a considerable amount of time to the already lengthy trip. I'd avoid that pain point if that's the choice.

How many 12 hour trips do you take? I hear this so much from people who only take one trip a year that would cause this hardship.

Re: What Needs to Happen Before Electric Cars Take Over the World

#423

Post by schiffern » Tue, Dec 19, 2017, 9:45 PM UTC

pilom wrote: post #420

schiffern wrote: post #320

Earlier quoted context omitted.

>> the superchargers take AC from the grid > the charger delivers exactly what the car needs You're both right. A Level 3 charger does deliver the right DC voltage the car needs, and it does so using power electronics that convert regular old grid AC into DC. Level 1 & Level 2 charging: AC grid -> cable -> onboard charger converts to 400V DC -> battery Level 3 charging: AC grid -> offboard charger converts to 400V DC…

Wouldn't there be an additional stepping at the transformer for level 1 and 2 chargers to go from AC distribution grid at 480V AC to 110V/220V where the level 3 superchargers can plug directly into the 480V AC mains without a transformer?

Yes, that's a great point. https://forums.tesla.com/forum/forums/updated-how-it-works-s...

For anyone that's confused, it's because now we're really getting into the weeds of how the grid works. :) It's only fair to look back and compare from the same point in the grid, in order to be an apples to apples comparison. Really we should look at the whole electricity supply chain.

Level 1 & 2 charging: high voltage AC transmission line -> local substation converts to 480V AC -> distribution lines (poles or buried) -> pole-mounted or buried transformer converts to 110/220V AC -> household wiring -> cable -> onboard charger converts to 400V DC -> battery

Level 3 charging: high voltage AC transmission line -> on-site transformer converts to 480V AC -> offboard charger converts to 400V DC -> cable -> battery

Re: What Needs to Happen Before Electric Cars Take Over the World

#424

Post by tkxxx7 » Tue, Dec 19, 2017, 9:47 PM UTC

Florin_Andrei wrote: post #415

twothamendment wrote: post #399

Earlier quoted context omitted.

How big would a battery have to be to get a dead EV off the side of the road and 25 miles to a charging station? Can a drone fly a 25 or 50 pound battery? What would the range on the drone be? I'm guessing a tow truck with the ability to charge a car is more likely.

What if the battery shipped by drone is what powers the drone itself? (I'm just trying to imagine some extreme scenarios, I'm not saying this is The Solution.)

I was going to say, flying, huge capacity battery == drone. It doesn't need to replace the car's battery, just charge it.

Re: What Needs to Happen Before Electric Cars Take Over the World

#425

Post by chc » Tue, Dec 19, 2017, 9:53 PM UTC

enraged_camel wrote: post #289

jdietrich wrote: post #242

Earlier quoted context omitted.

Electric cars have the potential to be a key part of the solution to load management on a fully renewable grid. The vast majority of people will usually charge overnight and don't need to regularly charge at peak times. Through intelligent charger management, you can distribute the load of charging across the entire off-peak period. The UX for this can be fairly straightforward - by default you charge at the cheapest…

I was talking to a professor of electrical engineering who performs research on the electric grid. She said that while in theory it is possible to configure cars to charge themselves when electricity is cheapest, currently residential utility plans don’t adjust pricing based on time of day. Your electricity bill’s tiers are based on your total consumption. Edit: lol, I get downvoted for relaying what a professor of E…

I don't think it is un-classy to downvote a comment that is substantially untrue.

Re: What Needs to Happen Before Electric Cars Take Over the World

#426

Post by chc » Tue, Dec 19, 2017, 10:00 PM UTC

civilitty wrote: post #311

vvanders wrote: post #294

Earlier quoted context omitted.

Yes, and standard chargers can be installed anywhere you can put a clothes dryer. You only need 120kW charging if you're going to be road-tripping. In the 2+ years I've owned an EV I've never had an issue, including doing 300mi+ in a single day about once a week. Heck, when I bought my current house I didn't need to do anything since the previous owner already had a NEMA 14-50 outlet for their welder.

Yeah it's all so simple until you realize that means every house running a clothes dryer all at the same time between 5pm and whatever time in the evening everyone is done charging. Los Angeles and parts of the Bay Area have had nearly annual brownouts for the last 20 years just from air conditioners during heat waves. How in the world do you expect that aging power grid (in the fifth/sixth largest economy no less...…

I imagine they'd handle it by designating off-peak hours, like many utility companies already do, so people will charge their cars then.

Re: What Needs to Happen Before Electric Cars Take Over the World

#427

Post by tomxor » Tue, Dec 19, 2017, 10:10 PM UTC

ecpottinger wrote: post #372

ghaff wrote: post #341

Earlier quoted context omitted.

People scraping together a few thousand dollars to buy a beater ICE so they can get to work are not doing TCO analyses. It's also a pretty open question what the cost of EVs looks like long-term. Even if we limit the discussion to new vehicles, you can buy a new ICE econobox for close to $15K which could last you 10 years and 150K miles fairly easily. I sure wouldn't bet on an electric car doing that on its original…

Then you will lose, the good EV cars have 90% of their battery life left after a lot more miles than that. See: https://www.greencarreports.com/news/1110149_tesla-model-s-b...

For 15k? he wont lose.

I think you and the parent commenter have different definitions of "scraping together a few thousand"... A Tesla model s might be sofa money for millionaires but it's unreachable to us filthy peasants thank you very much.

Try find a decent EV with a battery for longevity that is also affordable.

Re: What Needs to Happen Before Electric Cars Take Over the World

#428

Post by greglindahl » Tue, Dec 19, 2017, 10:26 PM UTC

polynomial wrote: post #416

greglindahl wrote: post #366

Earlier quoted context omitted.

Today's electric cars already have the ability to delay the start of charging. It doesn't need that smart of a grid, just a smartphone app.

How does this work in practice, with a high number of cars with such apps? Say everyone arrives home from commute at roughly the same time, how is the delay factor decided/distributed?

In the most interesting fantasy, the car has an idea of how much it actually needs to charge -- Bolts and Teslas often don't use but a small fraction of their battery on a typical day -- and the grid has an idea of how much wind energy it's going to get in the middle of the night. And you'd combine the two to make sure all of the wind energy gets put into a car battery, or car batteries don't end up full because the owners don't need it tomorrow and the wind is expected to be strong tomorrow evening.

You can do the same solar energy and cars plugged in during the daytime, soaking up excess solar electric generation.

Re: What Needs to Happen Before Electric Cars Take Over the World

#429

Post by fjsolwmv » Tue, Dec 19, 2017, 11:14 PM UTC

ChrisBland wrote: post #221

nickpeterson wrote: post #187

Earlier quoted context omitted.

I think the point is that since most people will charge at night, and capacity keeps improving, eventually if evs become really common, people will have less opportunity to buy something at a gas station.

Wait until you have kids and are traveling. There is always a snack that was forgotten, a meal missed, or something left at home.

That's not nearly enough to support running a store.

Re: What Needs to Happen Before Electric Cars Take Over the World

#430

Post by evgen » Tue, Dec 19, 2017, 11:18 PM UTC

twothamendment wrote: post #397

GiorgioG wrote: post #390

The issue of energy portability is not an insignificant one IMO. I can carry 5 gallons (or 100-150 miles worth of range) of fuel fairly easily. Not so much with an electric vehicle. What happens when I run out of juice on the side of the road? I don't care how many times the car warns me; that it shouldn't happen, etc. People still manage to run out of gas today. With an electric vehicle already hampered by half the…

In addition to fuel being portable, storage is important too. I can store extra fuel. When the power is out and the gas station can't pump - I don't care, I have a backup. I can put it in my truck, generator, etc.

And solar panels can both power your home and recharge your car. Indefinitely. What happens when you run out of extra fuel?