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EV batteries alone could satisfy short-term grid storage demand as early as 2030

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Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#251

Post by Ajedi32 »

powerbroker wrote: post #178
Ajedi32 wrote: post #18

Earlier quoted context omitted.

Unless it's voluntary (which it darned well better be). I envision a future where individual appliances (including EVs) can opt in to spot pricing for the electricity they consume (or produce). That would naturally incentivize charging during off-peak hours and discharging during peak hours, all without requiring any government incentives or coercion. It could also be useful for other major appliances which could ben…

>> I envision a future where individual appliances (including EVs) can opt in to spot pricing for the electricity they consume When 1,000 devices jump on the grid the moment electricity hits $0.01/kWh, the demand spike will cause more generators to come back on line and increase the price back to $0.05/kWh -- thus causing the 1,000 devices to drop-off the grid. Rinse, lather, repeat. How do you compensate for the pot…

Generators aren't going to spin up just to cover a brief fluctuation like that. It would cause too much wear on the system, so most likely anyone selling electricity to the grid via generators would program their system to only turn on when it predicts the price change will last more than a few seconds.

Assuming instability does actually become a problem though, that sounds like a very straightforward technical problem with many possible solutions. Just off the top of my head, the simplest market-based solution would likely be futures trading. If all these appliances reserve their electricity usage 10 seconds in advance, then sellers can know exactly how much demand there'll be and adjust their production accordingly, maybe even bidding on that capacity so they know in advance exactly how much they'll need to produce. I imagine the high-frequency trading industry probably has tons of experience with this sort of thing.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#252

Post by throwaway894345 »

manmal wrote: post #221
throwaway894345 wrote: post #159

Earlier quoted context omitted.

Your range figures seem pretty crazy high. Pretty sure most EV batteries are smaller than 100k--my Model Y is only 75k for instance, and I'm not getting anywhere close to 500km per cycle because (1) my Model Y doesn't actually get 500km on a full charge and more importantly (2) like most EV owners, I don't charge to 100% and run my battery down to 0% but rather something closer to 80%/20%. So for my Model Y scenario,…

There are 100kWh EVs out there, and they will quickly increase in number. For them, 500km is a rather conservative estimate. > I would expect them to get recycled and put back into cars In that case, you'd also get something in return for not having used those cycles. It's a matter of choice then - do I rent out my battery during use, or do I sell it after 8 years.

I don't doubt they exist, I doubt that they're common enough to treat as the general case.

> In that case, you'd also get something in return for not having used those cycles. It's a matter of choice then - do I rent out my battery during use, or do I sell it after 8 years.

Yeah, but which is more economical is the salient question.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#253

Post by coryrc »

manmal wrote: post #236
coryrc wrote: post #194

Earlier quoted context omitted.

When speaking of battery cycles and lifetime, people almost always mean "full cycle equivalent". So when you say "I only go 80%->20%" then that would be considered 0.6 cycles counted against the lifetime.

I don't, LFP batteries are quite resilient. 80% -> 20% is a usability nightmare nobody with a $50k vehicle should accept. My Ioniq (first gen) doesn't even have an LFP battery and is optimized for 100% -> 13%, maybe even 100% -> 10% (turtle mode starts at 5%). Still at 100% SOH after three years. Way more important for battery life is the charging rate (again, LFP are more resilient there too). Which wouldn't be an i…

I think you do. If you drove 10 miles and recharged, you wouldn't consider that a "cycle". You could do that 100k times (probably more), but no one would say the battery cycle life is 100k.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#254

Post by mercutio2 »

danans wrote: post #183
mercutio2 wrote: post #155

Earlier quoted context omitted.

How do you like your Enphase batteries? I was pondering buying them, already have Enphase solar. I'm particularly interested in whether you're doing any load-shifting with them, and if so, how easy it is to do with the software. I'm paying $.90/kWh at summer peak, so while I'm still on net-metering, I'm somewhat interested in going ahead and fully arbitraging during peak.

> How do you like your Enphase batteries? I'm mostly happy with them. The batteries are pretty much set-and-forget, but I change the reserve level by season (90% in winter, 30% in summer). The system automatically decides how to do load shifting to optimize for your particular rate structure. I will say the monitoring software can be janky at times. It's gotten better, but sometimes it is very slow to connect to the…

I live in Berkeley. PG&E’s peak EV-A rate for generation plus distribution was $.92 this summer. It doubled in a year or two.

My off peak rate for charging the car went from net $.15/kWh to $.36 during the summer.

It’s news to me that load shifting (if you’ve got batteries and solar) isn’t allowed by the CPUC, that does take the wind out of my sails a bit. But the peak rates are so high that just zeroing out my peak consumption is still probably worth it.

Does the system come with a “disconnect from the grid during emergencies” shunt?

I’ve heard conflicting reports about the availability and legality of those systems.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#255

Post by throwaway894345 »

coryrc wrote: post #194
throwaway894345 wrote: post #159

Earlier quoted context omitted.

Your range figures seem pretty crazy high. Pretty sure most EV batteries are smaller than 100k--my Model Y is only 75k for instance, and I'm not getting anywhere close to 500km per cycle because (1) my Model Y doesn't actually get 500km on a full charge and more importantly (2) like most EV owners, I don't charge to 100% and run my battery down to 0% but rather something closer to 80%/20%. So for my Model Y scenario,…

When speaking of battery cycles and lifetime, people almost always mean "full cycle equivalent". So when you say "I only go 80%->20%" then that would be considered 0.6 cycles counted against the lifetime.

Is that how it works? Can I just charge every night, even if I've only driven a few miles, with no more wear on my battery than if I did full cycle charges? My vague impression is "no", but I really have no idea.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#256

Post by dokem »

geysersam wrote: post #208
dokem wrote: post #141

Earlier quoted context omitted.

Imagine thinking the government or big-business would sell a money making machine. Why not capture it themselves?

Car owners already have these huge batteries. For any other actor that would be a huge capital expense.

It's nothing compared to the cost of building and maintaining the grid. You're not on equal footing with a power company just because you have some batteries. A battery in your garage isn't meaningful capital to produce passive income. This isn't how economics works.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#257

Post by zdragnar »

fomine3 wrote: post #199
zdragnar wrote: post #196

Earlier quoted context omitted.

1,000 cycles is only 3 years (assuming a daytime commute plus discharging to the grid plus re-charging back up counts as a cycle). Most cars are definitely still under warranty after 3 years of driving (assuming a 5 year / 50k mile warranty). Regardless, if you do have a high mileage ICE car that you want to save, the used engine is probably the way to go, and won't suffer a crippled range of a used battery. In gener…

Cycle count is counted for every 0-100 charge/use. 1000 cycles in 3 years is unlikely for normal home use.

So, assuming commute + feed into the grid + recharge, it's closer to 5 or 6 years, and only the first two or three are under warranty?

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#258

Post by manmal »

coryrc wrote: post #253
manmal wrote: post #236

Earlier quoted context omitted.

I don't, LFP batteries are quite resilient. 80% -> 20% is a usability nightmare nobody with a $50k vehicle should accept. My Ioniq (first gen) doesn't even have an LFP battery and is optimized for 100% -> 13%, maybe even 100% -> 10% (turtle mode starts at 5%). Still at 100% SOH after three years. Way more important for battery life is the charging rate (again, LFP are more resilient there too). Which wouldn't be an i…

I think you do. If you drove 10 miles and recharged, you wouldn't consider that a "cycle". You could do that 100k times (probably more), but no one would say the battery cycle life is 100k.

I mean I didn’t count in 0.6 cycles per discharge. My battery does 0.9-0.95 cycles usually.

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#259

Post by manmal »

throwaway894345 wrote: post #252
manmal wrote: post #221

Earlier quoted context omitted.

There are 100kWh EVs out there, and they will quickly increase in number. For them, 500km is a rather conservative estimate. > I would expect them to get recycled and put back into cars In that case, you'd also get something in return for not having used those cycles. It's a matter of choice then - do I rent out my battery during use, or do I sell it after 8 years.

I don't doubt they exist, I doubt that they're common enough to treat as the general case. > In that case, you'd also get something in return for not having used those cycles. It's a matter of choice then - do I rent out my battery during use, or do I sell it after 8 years. Yeah, but which is more economical is the salient question.

I agree, that’s an interesting question. You‘d need to factor in a fair bit of uncertainty due to inflation, future battery prices etc

Re: EV batteries alone could satisfy short-term grid storage demand as early as 2030

#260

Post by danans »

mercutio2 wrote: post #254
danans wrote: post #183

Earlier quoted context omitted.

> How do you like your Enphase batteries? I'm mostly happy with them. The batteries are pretty much set-and-forget, but I change the reserve level by season (90% in winter, 30% in summer). The system automatically decides how to do load shifting to optimize for your particular rate structure. I will say the monitoring software can be janky at times. It's gotten better, but sometimes it is very slow to connect to the…

I live in Berkeley. PG&E’s peak EV-A rate for generation plus distribution was $.92 this summer. It doubled in a year or two. My off peak rate for charging the car went from net $.15/kWh to $.36 during the summer. It’s news to me that load shifting (if you’ve got batteries and solar) isn’t allowed by the CPUC, that does take the wind out of my sails a bit. But the peak rates are so high that just zeroing out my peak…

> I live in Berkeley. PG&E’s peak EV-A rate for generation plus distribution was $.92 this summer

I live in the same service area. The peak EV2A rate (including both generation and distribution) is currently $0.55/kWh, and the off-peak is $0.24/kWh.

https://www.pge.com/en_US/residential/rate-plans/rate-plan-o...

Not sure where you are getting $0.92/kWh, but would be curious to learn.

> It’s news to me that load shifting (if you’ve got batteries and solar) isn’t allowed by the CPUC, that does take the wind out of my sails a bit. But the peak rates are so high that just zeroing out my peak consumption is still probably worth it.

Load shifting in the sense of shifting your load to different times to consume cleaner/cheaper electricity from the grid, is fine and even encouraged by the CPUC. There are all kinds of programs to encourage this. You can achieve this by simple behavioral changes, timed appliance runs, or by using battery storage.

What you can't do as an individual homeowner, AFAIK, is arbitrage power by buying low from the grid and selling back high to the grid later.

> Does the system come with a “disconnect from the grid during emergencies” shunt?

> I’ve heard conflicting reports about the availability and legality of those systems.

The only "emergency" that causes a disconnect is a power outage. That's no different than what solar inverters already do. The difference with the batteries is that when that happens, they form an isolated microgrid on your premises, thereby providing backup for that scenario.

What other sort of emergencies were you imagining? If you mean minimizing grid load during peak grid load events, then that's what the virtual peaker programs do, and those are completely legal, and active participants in the CAISO energy markets.

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