Falling lithium-ion battery prices to drive rapid storage uptake • Hacker News Board

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#101

Post by epistasis » Thu, Aug 03, 2017, 8:11 PM UTC

Florin_Andrei wrote: post #86

epistasis wrote: post #25

Earlier quoted context omitted.

Your instincts would be wrong on this one. This is a technical article, that talks about all the right things for grid storage: value stacking, $/kWh (note the h), various install locations such as behind-the-meter, etc. They know what they are talking about. Currently, grid discussions happen mostly in the MW or GW space. Maximum instantaneous discharge speed is pretty much the most important characteristic for stor…

> They know what they are talking about. In this article, which is what we're discussing here, it is very clearly either a typo, or it's some journalist spouting off above their pay grade.

Why do you think that? I read a lot of about grid storage, and I can't come to the same conclusion as you on this one. It's very common to talk about GW in isolation of GWh for storage systems in the press, and for GW to be talked about before GWh.

And if you're used to thinking about utilities, it makes a lot of sense, you think about power capacity, and then the duration afterwards. GW is a more direct way to approach that. If you want to get duration from GWh and GW, you have to do a mental division, which is slower than multiplication.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#102

Post by mtgx » Thu, Aug 03, 2017, 8:15 PM UTC

ChuckMcM wrote: post #52

baybal2 wrote: post #40

Earlier quoted context omitted.

>I wonder how much of this is simply the Gigafactory coming online at full production + others trying to keep their factories running. The "Gigafactory," is a drop in the ocean if you count noname Chinese factories, but it will be one of the biggest market players outside of China

We have different ideas about 'drops in the ocean' :-) See this article ( http://fortune.com/2017/06/28/elon-musk-china-battery/ ) for some numbers. Projected Gigafactory production (as more come on line) could continue to be 25 to 35% of the global production of batteries. My father-in-law, who is a big booster of South America, feels that if Argentina, Brazil, and Chile got together they could move up the 'value ch…

Also Musk has said that he's considering building 2-3 more gigafactories, but we don't know how fast those will be built. It could be over the next decade or so.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#103

Post by agumonkey » Thu, Aug 03, 2017, 8:16 PM UTC

Zekio wrote: post #87

toomuchtodo wrote: post #58

Earlier quoted context omitted.

The Gigafactory operates seven days a week with two shifts.

didn't they change it to three shifts to reduce injuries because of human error from being tired

I heard they wanted better safety but didn't think they meant "more sleep".

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#104

Post by pjc50 » Thu, Aug 03, 2017, 8:21 PM UTC

skummetmaelk wrote: post #31

merpnderp wrote: post #3

Earlier quoted context omitted.

That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. The hottest part of the day usually starts at about the end of the prime solar hours. Plus you'll want massive overcapacity of your batteries as deep discharges drastically reduce their useful lifespan.

100 kWh/day is just incredible. The average consumption per person in the nordics is about 1500 kWh per YEAR.

That doesn't quite seem right: http://shrinkthatfootprint.com/average-household-electricity...

(Interestingly Canada's per capita consumption is comparable to the US despite being much further north)

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#105

Post by pjc50 » Thu, Aug 03, 2017, 8:24 PM UTC

derefr wrote: post #39

Hah, I misinterpreted "storage" here, and thought this was going to be about Li-ion cells getting cheap enough to replace the capacitors in the Power Loss Protection circuits in hard drives/SSDs/NVMe boards. Which doesn't make sense, after giving it a second's thought—batteries wear out after just a few years, while capacitors (very nearly) don't, so it'd put a hard lifetime on drives. (Though, for server use-cases w…

> kept the disks alive for up to, say, 30 minutes after power loss

Not relevant to disks, but you could have battery-backed DRAM? Commonly used in RAID clusters as a cache.

The main problem with storage architecture is too much hardware that lies about whether it's actually committed a write.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#106

Post by fenwick67 » Thu, Aug 03, 2017, 8:28 PM UTC

epistasis wrote: post #25

ptero wrote: post #18

Earlier quoted context omitted.

Maximum discharge speed (which is one of the very few storage characteristics I can think of to be measured in GW) is pretty much irrelevant for storage systems. Add a few quick discharge capacitors that cost almost nothing and boom -- your max discharge speed shoots through the roof (but speed goes down for a very short time). Maybe sustained charge speed is a (little bit) more meaningful thing you can express in GB…

Your instincts would be wrong on this one. This is a technical article, that talks about all the right things for grid storage: value stacking, $/kWh (note the h), various install locations such as behind-the-meter, etc. They know what they are talking about. Currently, grid discussions happen mostly in the MW or GW space. Maximum instantaneous discharge speed is pretty much the most important characteristic for stor…

I think what threw me off was when they say "capacity".

I don't work in power systems, I work with low-voltage DC stuff, so when I think "the capacity of the battery system" I think it would mean the maximum stored energy.

But "The maximum amount that can be produced" is also a valid definition of capacity, and I'm guessing this definition might be used in power generation more often ("the generator is operating at half capacity").

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#107

Post by Florin_Andrei » Thu, Aug 03, 2017, 8:37 PM UTC

epistasis wrote: post #97

Florin_Andrei wrote: post #79

Earlier quoted context omitted.

> GW is, however, a characteristic of an energy storage system, and just a valid and important measurement as the amount of energy it stores. Wrong. The watt is a measure of power, not of stored energy. These are different physical notions. So, yes, you could say that some storage facility can output up to so many GW, but that's actually a measure of how much energy per second can exit the system when it's being used…

>Wrong. At no point do you actually say what was wrong about what you quoted. What do you feel is in error? >GWh is static energy (or simply - energy). GW is energy moving from point A to point B, which is power. Yes, obviously. This is HN. Generally it pays to assume that people know what they are talking about around here. It may be that you don't care about the power rating of the storage instance, but a utility d…

> At no point do you actually say what was wrong about what you quoted. What do you feel is in error?

The whole comment past that point is an explanation why that statement is wrong. Read it.

You're clearly confused about the difference between power and energy. There's no meaningful discussion on this topic until you figure that out.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#108

Post by adrianmonk » Thu, Aug 03, 2017, 8:40 PM UTC

aphextron wrote: post #65

_JamesA_ wrote: post #54

Earlier quoted context omitted.

The Texas summer is brutal [1]. Last month my average home used between 100 and 120 kwh per day [2]. Luckily we rarely have to heat in the winter - although it's not uncommon to have the A/C running for Christmas. [1]: http://www.statesman.com/news/local/wipe-that-brow-austin-re... [2]: http://imgur.com/a/45oGu

>Last month my average home used between 100 and 120 kwh per day [2]. That's half of my entire energy usage for a month... Have you considered a swamp cooler?

Swamp coolers work in areas that are hot and dry, like New Mexico or Arizona.

They do not work well if it's hot and humid, for two reasons. One is that the water doesn't evaporate as well, so they don't cool well. The other is that the whole point is comfort, and in a humid climate you don't achieve that unless you remove both heat AND humidity, but swamp coolers add humidity.

Texas has some desert areas (western part of the state), but most of the population lives in the part of the state that isn't a desert.

The good news is with modern construction techniques and equipment, you can cut energy usage WAY down. You can cut energy usage a lot with stuff like a radiant barrier in the attic, attic vents, lots of insulation, double pane windows, a "tight" house with little air leakage, proper angles to keep direct sun from heating up the house at the wrong times, and a high-efficiency AC unit that you service and maintain properly. In fact, a lot of those things are actually more beneficial than getting solar panels.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#109

Post by Florin_Andrei » Thu, Aug 03, 2017, 8:40 PM UTC

fiter wrote: post #100

Florin_Andrei wrote: post #79

Earlier quoted context omitted.

> GW is, however, a characteristic of an energy storage system, and just a valid and important measurement as the amount of energy it stores. Wrong. The watt is a measure of power, not of stored energy. These are different physical notions. So, yes, you could say that some storage facility can output up to so many GW, but that's actually a measure of how much energy per second can exit the system when it's being used…

GW is a very important characteristic of an energy storage system, especially as a ratio of GWh. A technology could store 100TWh, but if it can only release 1kW, I'm not interested. The comment you replied to said "just a valid and important measurement as the amount of energy it stores". The comment didn't say power was the same thing as energy, it says that the power is as important as the energy. I don't think thi…

Let me quote that thing for you again. Parse is again, more slowly this time, and see for yourself:

> GW is [...] a valid and important measurement as the amount of energy it stores

There's no way to sugarcoat it. This is like saying km/h is a measurement of distance.

Re: Falling lithium-ion battery prices to drive rapid storage uptake

#110

Post by sliverstorm » Thu, Aug 03, 2017, 8:47 PM UTC

comicjk wrote: post #38

Using lithium-ion batteries for stationary storage is interesting because their original advantage was all about light weight (lithium is the lightest metal element). Now, it seems the development effort devoted to lithium-ion has paid off so well that they are the best OVERALL battery solution. The single-minded effort we put into cell phones and cars is so strong that it now reaches all the way to homes and the gri…

We do this a lot. CCD image sensors are inherently more suited to astrophotography, but so much development has been put into CMOS that it is catching up to (and may surpass) CCD. A single widespread technology, with more applications & development effort, surpasses a better but more niche technology.

It's an interesting phenomenon. In the case of batteries, I wonder if we fully account for all the costs though. Lead-acid, for example, is a very sustainable (long-lasting, highly recyclable) battery technology that is inherently suitable, but if the full mining/recycling/disposal costs of lithium-ion are not priced in, the market won't account for this.