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EVs Are Essential Grid-Scale Storage

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Re: EVs Are Essential Grid-Scale Storage

#201

Post by mnw21cam »

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…

I made this argument a few years ago when my wife asked me if it was a good idea for us to get solar panels for the house. My reply was that solar farms get economy of scale and would out-compete us, plus our roof views East/West, not South. Now that electricity prices have trebled, I have changed my mind.

The simple fact is that these static larger installations should be better, but they're not happening at nearly high enough rate, and so there is still benefit to be had by individuals installing smaller less efficient systems.

Re: EVs Are Essential Grid-Scale Storage

#202

Post by driverdan »

coding123 wrote: post #172
discordance wrote: post #4

Earlier quoted context omitted.

$300/kWh for home storage is readily available. E.g. https://signaturesolar.com/eg4-ll-lithium-battery-24v-200ah/

Those 5kwh "server" batteries are overpriced compared to prismatic cells and a bms.

They aren't when you factor in labor and the other components involved (wiring, breakers, terminals, steel box, etc). I've built my own system in my RV but will be going with racked batteries for my house due to how much time and effort they will save.

Re: EVs Are Essential Grid-Scale Storage

#203

Post by thrashh »

londons_explore wrote: post #25
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…

Luckily, any degradation can all be predicted ahead of time. A 60kwh car battery might cost $10k, and allow 2000 charge cycles. So each kwh cycled into and out of the battery costs 8 cents. So a smart algorithm can decide it's worth draining the battery back into the grid if the profit to be made is more than 8 cents. Buuuut ... Delaying charging till later is free. So another car owner's car might see on the futures…

It may be calculable, but is it economical? That 8 cents isn't free. If the power company pays, that means customers pay. If customers don't pay, society has to pay. There are other power storage solutions like pumped hydro that don't have to deal with battery chemistry degradation, for example, but they have higher investment costs.

This study is great but a energy storage comparison study that calculates total cost would tell us much more. Wouldn't be surprised if the Department of Energy already has or is [1]

[1] They do a lot of these studies already. i.e. https://iea.blob.core.windows.net/assets/ae17da3d-e8a5-4163-...

Re: EVs Are Essential Grid-Scale Storage

#204

Post by appletrotter »

theluketaylor wrote: post #124
danuker wrote: post #44

Earlier quoted context omitted.

It worries me that if industrial-purpose batteries cost the same and have similar degradation, grid services will also decide not to charge/discharge if the profit is less than 8 cents. This tells me that Li-Ion batteries are far from the ideal medium for grid storage.

Most cars use NCA or NMC chemistry which has 500ish cycles. Grid storage will soon use LFP which is cheaper to begin with and has 5000+ cycles. It has a lower density than other chemistries and very poor cold weather performance, making it less ideal for vehicles (though Tesla is using it in the standard range model 3 now). Those downsides don't matter for grid storage and really change the economics of charge/discha…

> has 500ish cycles

That's on the low end, like if you're fully charging/discharging the battery frequently.

Re: EVs Are Essential Grid-Scale Storage

#205

Post by kragen »

devmor wrote: post #85
danuker wrote: post #44

Earlier quoted context omitted.

It worries me that if industrial-purpose batteries cost the same and have similar degradation, grid services will also decide not to charge/discharge if the profit is less than 8 cents. This tells me that Li-Ion batteries are far from the ideal medium for grid storage.

Batteries are extremely inefficient. Capacitors are much more resilient in terms of charge cycles (by orders of magnitude). If one were to build a "facility" to hold short term load, that's likely what they'd use. They just can't be used in cars because they're incredibly volatile and don't hold a charge for a long period of time.

capacitors are very low energy density and very high cost per joule of storage so they are never used this way

Re: EVs Are Essential Grid-Scale Storage

#206

Post by iso1210 »

sokoloff wrote: post #176
iso1210 wrote: post #81

Earlier quoted context omitted.

This does work today at grid scale, people use their home batteries (either on wheels or not) to charge/discharge to the grid in the UK all the time. If someone builds that storage facility to do it commercially then great. > rooftop solar can't exist without special subsidies Yet it does

There are special subsidies for rooftop solar here in the US (Solar Investment Tax Credit). Are there not subsidies for solar where you live? https://www.seia.org/initiatives/solar-investment-tax-credit... > The solar Investment Tax Credit (ITC) is one of the most important federal policy mechanisms to support the growth of solar energy in the United States. Since the ITC was enacted in 2006, the U.S. solar industry…

Not any more, other than no sales tax on the panels.

Re: EVs Are Essential Grid-Scale Storage

#207

Post by ceejayoz »

guruz wrote: post #181
ceejayoz wrote: post #131

Earlier quoted context omitted.

I might want a car with 300 miles charge for vacations, but most of the time be making trips to the grocery store. The grid might only dip into my car's battery for a 15-30 minutes at a time to prevent brown-outs while power plants spin up. There are plenty of scenarios where the EV makes more sense than a dedicated battery for it.

You might be at work (away with car) while the midday sun is filling your home battery.

Sure, if you have solar, by all means get a home battery and enroll it in the same grid backup program. Makes plenty of sense.

In my case, I live on a very shaded property; no solar for me. I also live next to an electrical substation, so extended outages from storms is highly unlikely; I'm first on the fixed list every time. In my case, the home battery doesn't make sense, but the EV might still.

EVs as grid storage is an option that may be compelling in some areas and for some people. I think that's worth exploring.

Re: EVs Are Essential Grid-Scale Storage

#208

Post by thescriptkiddie »

mnw21cam wrote: post #200
discordance wrote: post #4

Earlier quoted context omitted.

$300/kWh for home storage is readily available. E.g. https://signaturesolar.com/eg4-ll-lithium-battery-24v-200ah/

Deep cycle lead-acid batteries are available around £100/kWh, and they'll last pretty-much as long as a LiFePo if managed sensibly.

> they'll last pretty-much as long as a LiFePo

citation needed

Re: EVs Are Essential Grid-Scale Storage

#209

Post by fcantournet »

adrianN wrote: post #34
Maxion wrote: post #13

Unless the $/kwh or lifecycle count of EV batteries change significantly, using them as a grid-scale storage is just not financially feasible. E.g. a NMC battery has a lifespan of around ~2000 cycles, a model S 90 D has a 90 kWh battery. That's around 180 MWh of total energy that can be moved through the battery before it is dead. On Reddit, a tesla user reports ( https://www.reddit.com/r/teslamotors/comments/v4dqkp/…

It's not cheaper to run a natural gas power plant if you want to be carbon neutral. Then you have to run it with hydrogen, which is quite expensive to make. It also gets more expensive if you only want to run the gas plant a couple of hours per month because at all other times renewable power is sufficient.

It is cheaper to run a nuclear power plant though. Like a lot. Also uses about 50x less material per MWh

Re: EVs Are Essential Grid-Scale Storage

#210

Post by panick21_ »

This would require quite a bit of hardware on both cars and houses to work. And in many ways doing both backup to the house and being able to feed into the grid is pretty damn hard.

So I will be surprised if this happens on large scale. This is an idea that sound great on paper but there are really a lot of practical issue between where we are now and in this ideal future.

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