EVs Are Essential Grid-Scale Storage • Hacker News Board

Re: EVs Are Essential Grid-Scale Storage

#61

Post by dtech » Wed, Jan 25, 2023, 2:11 PM UTC

causi wrote: post #23

Even if you completely do away with concerns of battery wear, I'd only be willing to participate in this as long as my household still had an ICE vehicle to fall back on. When I get home and plug the car in I don't want to have to think about whether I might want or need to leave the house at a particular time with a particular charge; I just want the charge to be as high as possible as soon as possible.

That is going to be an expensive habit in the future once time-variable pricing is the standard, which I think is inevitable. Charging your car at 6PM is going to be super expensive compared to 3 AM or 1 PM.

Also note you'll still have fast-chargers, you don't always need to charge immediately at full capacity at home, just as you wouldn't always top up on gas after every drive.

Re: EVs Are Essential Grid-Scale Storage

#62

Post by greenthrow » Wed, Jan 25, 2023, 2:11 PM UTC

Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

We are not talking about multiple 0-100% cycles daily. The places where pilot programs have been run always left the car with some amount of charge so it can be driven, and you don't normally charge NMC car batteries to 100%.

Vehicle batteries have 8 year 100k mile warranties today, and those manufacturers who have spoken on this topic have said that utilizing your battery as grid storage will not violate the warranty (Ford said this about the Lightning, which can do V2G today.)

Please stop spreading misinformation and go do some research before you spout FUD like this.

Re: EVs Are Essential Grid-Scale Storage

#63

Post by coffeebeqn » Wed, Jan 25, 2023, 2:15 PM UTC

college_physics wrote: post #60

This feels gimmicky and fragile. If distributed / decentralized storage is required (sounds like a good idea overall) it is surely better to have stationary installations, with larger batteries and connectivity optimized for that purpose, not using the EV batteries currently developed for moving these two-ton exosceletons to random places... In fact you want to have the option to significantly reduce EV usage as othe…

It is gimmicky but the batteries in EVs are really big and especially in the US everyone has a car. I don’t see a large amount of houses getting a 30-70kWh battery unless they install rooftop solar. So what are the realistic options ? Other than large infrastructure spend to get grid batteries which is probably what will happen in the end

Re: EVs Are Essential Grid-Scale Storage

#64

Post by sharemywin » Wed, Jan 25, 2023, 2:16 PM UTC

raxxorraxor wrote: post #2

I don't understand the discrepancy between EV kWh and house battery kWh. Some cars have > 100 kWh capacity. Why do I pay > 1000$ per kWh for a house battery? At some point it is cheaper to just buy a car, even if you would never drive it. A Tesla Powerwall has 13 or so kWh? Why don't they use the car battery with nearly 10 times as much capacity? It is just unit prices that are far better for cars? Is the charge/disc…

State level regulations around installation driving up prices?

Re: EVs Are Essential Grid-Scale Storage

#65

Post by TheLoafOfBread » Wed, Jan 25, 2023, 2:16 PM UTC

What a joke. Renewables intermittency is not a problem of a user, but problem of the operator of renewable power plant. Government should mandate that any renewable power plant must provide installed power (i.e. 100MW) for at least 24 hours without interruption, independently on weather and if it can't because operator cheapen out on power plant's energy storage, sanction them until bankruptcy.

Re: EVs Are Essential Grid-Scale Storage

#66

Post by londons_explore » Wed, Jan 25, 2023, 2:16 PM UTC

pclmulqdq wrote: post #47

londons_explore wrote: post #30

Earlier quoted context omitted.

> 106 USD per MWh hour, which is more than most generation sources Minute by minute electricity prices vary really widely. It isn't unusual for prices to spike up 10x briefly at peak times. Most power stations have too high a capital cost to only run 2% of the time... whereas your tesla battery has no capital cost, so using it to power the grid 2% of the time when the prices are sky-high is very attractive.

So people being asked to discharge their Tesla into the grid should be paid a significant premium, right? Since they are providing power on demand in a way that doesn't have upfront costs, that should mean that car-based power demands a cloud-like premium (10-50x over traditional servers) over traditional power plants. They are getting a little premium today, but likely won't once this practice becomes normal.

It's a market - so whoever is willing to do the task for the smallest premium gets the business...

Re: EVs Are Essential Grid-Scale Storage

#67

Post by dtech » Wed, Jan 25, 2023, 2:16 PM UTC

dahfizz wrote: post #57

This boils down to "There are lots of EV batteries, we can use them as storage!". It seems to ignore practical issues: People drive during the day, and charge at night. So you could use EVs as a buffer during the night, but they still need to be charged. So EVs are still going to be a net energy consumer during the night, when you need the storage the most (no solar production). I think the best course of action is t…

Every ignoring that most cars aren't used every day, most cars are parked during the day and peak solar generation time.

Re: EVs Are Essential Grid-Scale Storage

#68

Post by bluGill » Wed, Jan 25, 2023, 2:19 PM UTC

Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

You are missing something: lifetime depends on how much you cycle the battery. If you take the battery from 80% to 50% 5 times feeding the grid you do a lot less damage to the lifetime than just one 100% to 0% cycle, even though the first supplied more power overall to the grid. Smart management of batteries can ensure that this happens.

Re: EVs Are Essential Grid-Scale Storage

#69

Post by dahfizz » Wed, Jan 25, 2023, 2:19 PM UTC

schiffern wrote: post #40

Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

> instead of a single top up change it is now constantly discharging and charging This is where V1G beats V2G. V1G (AKA grid-adaptive charging) just chooses when to charge the car, to efficiently spread out the grid load overnight and spatially across the network. No extra charge cycles, in fact it's probably more mild than just charging at full speed. The key is that you need a UI setting for "Immediately charge to…

> Or better yet, owners set their car to only "bid" for a grid storage job when the cost-per-kWh is greater than the cost of degradation.

It would have to be substantially greater. I'm not going to deal with reduced battery capacity and the hassle of replacing it early for a couple of cents here and there.

Considering the extra cost of equipment to allow the EV to send power to the grid, I don't think the economics will ever work out.

Re: EVs Are Essential Grid-Scale Storage

#70

Post by Maxion » Wed, Jan 25, 2023, 2:21 PM UTC

dtech wrote: post #54

Maxion wrote: post #45

Earlier quoted context omitted.

My point is mainly that there are plenty of options available to stabilize grid prices that are way cheaper than using EV's. Europes energy crisis is temporary, over time the price fluctuations will go down.

which other options are feasible today outside hydro pumping?

Isn't that the big question? Whoever is confident that they have correct answer to that question should invest any coin they can get their hand on right this second.

Purely from a theoretical perspective, anything that can generate power at lower prices than the current market rate will be financially viable. With this past winters prices in Europe, it means literally anything. Even at times a diesel generator from your local hardware store would be a good idea (~.60 EUR per kWh).

But these prices won't last, in a few years we will be already back down to manageable price fluctuations.

It's pretty easy to see though that if battery based grid storage is going to be a big thing, it is not going to be EV batteries. The chemistry used in them is not optimized for life cycles (at least currently). LFP chemistry batteris that are in some Teslas has bettery cycle duration. Sodium Ion batteries will most likely be the choice for grid-scale deployment if they can be commercialized.