Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Falling lithium-ion battery prices to drive rapid storage uptake

pv-magazine-usa.com

Post reply on HN
Print view View original

151–160 of 187 posts

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

#151

Post by gwbas1c »

thescriptkiddie wrote: post #126
ChuckMcM wrote: post #35

I wonder how much of this is simply the Gigafactory coming online at full production + others trying to keep their factories running. If you look at Tesla's plan to be making 10,000 model 3's a week, with a nominal 90 kWh battery in each that is 900 MWh a week of capacity or 46 GWh capacity a year. But it is all tied up in cars of course[1]. The power companies have been screwing around with rate plans to keep grid-t…

Utilities are actually planning on using parked electric cars for storage. https://en.wikipedia.org/wiki/Vehicle-to-grid

Hell no!

As soon as someone departs for a long trip and the battery isn't charged, there will be a huge class action lawsuit.

The lemon law attorneys will also have a field day!

This is a really dumb idea.

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

#152

Post by StillBored »

wongarsu wrote: post #48
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…

Keeping the disks alive is certainly doable. At a rough estimate of 10W per drive, even storage servers would only need very moderate batteries. But what would you gain by that? More interesting (in my eyes) would be to power down spinning disks and processors, but keep caches and ram alive. Then once power is restored, you could basically supply power and continue where you left off, without any reboots etc. Then ag…

Congratulations, you just invented the ACPI S3 power state. Also known as standby or suspend to ram. I've been pretty happy with it since ~1998 when I started returning hardware that didn't support it properly. Although these days even linux on a laptop tends to work properly with S3 and S4 (hibernate, or suspend to disk). That said the concept was also part of the earlier APM standard which was a lot more hit/miss.

Anyway, its great, I used it today to ride out a nearly hour long power outage with a couple of fairly trivial UPSs connected to my NAS, desktop, etc. The desktop was already in standby because that is its default state after being idle for 30 mins. But the NAS went into that mode when the UPS indicated 70% battery life.

The problem of course is that UPSs/etc have miserable power conversion efficiencies when supplying just a couple watts of power, like 10-30% efficiency, so they tend to have max run-times less than 2 hours even when completely unloaded.

More on point, for servers, if your server is lightly loaded, or loaded for only parts of the day, using WOL to wake it and going into standby after a few minutes can save a fair amount of power. With SSDs, the resume times are generally less than a second unless you have bad cards/drivers that take forever to reinit.

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

#153

Post by [deleted] »

Gracana wrote: post #9
epistasis wrote: post #7

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.

The maximum output is interesting to know, but if you asked how much my car's fuel tank held and I told you "100mph," you'd be understandably confused.

[deleted]

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

#154

Post by mulmen »

Gracana wrote: post #9
epistasis wrote: post #7

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.

The maximum output is interesting to know, but if you asked how much my car's fuel tank held and I told you "100mph," you'd be understandably confused.

A watt is a measure of power, not distance. The equivalent unit for a car would be horsepower. You could express the capacity of your fuel tank in horsepower hours. Since both are measurements of power and horsepower is defined in terms of watts you could even measure the capacity of your fuel tank in kilowatt hours. Similarly, you can define the output of your engine in kilowatts.

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

#155

Post by derefr »

aarongough wrote: post #82
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…

If you have a look through some of the Google datacenter tours you'll see they actually implement this idea on a massive scale, though I believe they use lead-acid batteries... Every motherboard in the datacenter has a small battery capable of powering it for a long enough period of time for the backup generators to kick on and take over. It's definitely a clever idea! Makes maintenance much less risky as it's distri…

I guess the hardware does exist, but I was thinking of a different use-case for it: not for fault-tolerance per se (i.e. waiting for the power to come back on or the generator to kick in), but rather for giving the disk cache up to 30 minutes (after the rest of the machine is well-and-truly cut from power) to flush to the disk itself before finally shutting off, rather than a few seconds to empty its pending writes and park the disk head.

You could, therefore, have a really, really big disk cache, and a relatively slow-to-flush disk. With such an architecture, you could build systems that use disk+cache the way Optane NVMe is being used, without having even needed to invent Flash memory to get fast, highly-parallel writes first.

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

#156

Post by dredmorbius »

k__ wrote: post #67
agumonkey wrote: post #57

Earlier quoted context omitted.

Will the GigaFactory operate on weekends ? 1400~ car per day .. I'd love to see that on video.

What is this? 1 car per minute?

1,440 min/day.

86,400 sec/day

So, yes.

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

#157

Post by vanattab »

thescriptkiddie wrote: post #126
ChuckMcM wrote: post #35

I wonder how much of this is simply the Gigafactory coming online at full production + others trying to keep their factories running. If you look at Tesla's plan to be making 10,000 model 3's a week, with a nominal 90 kWh battery in each that is 900 MWh a week of capacity or 46 GWh capacity a year. But it is all tied up in cars of course[1]. The power companies have been screwing around with rate plans to keep grid-t…

Utilities are actually planning on using parked electric cars for storage. https://en.wikipedia.org/wiki/Vehicle-to-grid

Wouldn't this wear out the battery life?

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

#158

Post by [deleted] »

thescriptkiddie wrote: post #126
ChuckMcM wrote: post #35

I wonder how much of this is simply the Gigafactory coming online at full production + others trying to keep their factories running. If you look at Tesla's plan to be making 10,000 model 3's a week, with a nominal 90 kWh battery in each that is 900 MWh a week of capacity or 46 GWh capacity a year. But it is all tied up in cars of course[1]. The power companies have been screwing around with rate plans to keep grid-t…

Utilities are actually planning on using parked electric cars for storage. https://en.wikipedia.org/wiki/Vehicle-to-grid

[deleted]

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

#159

Post by Hasz »

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…

LiS will be even more popular with grid utilities. Super high specific energy, but low overall discharge weight + low cost of Sulfur means a popular, stationary battery perfect for grid tie in. Ironically, it's even less dense than li-ion.

The current issue is commercialization (i.e, doesn't exist) and low conductivity of the sulfur cathode (meaning a low discharge rate to avoid self heating) -- it could be a decade + away.

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

#160

Post by hedora »

baybal2 wrote: post #61
ChuckMcM wrote: post #52

Earlier quoted context omitted.

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…

I have no idea of where they get those digits. Chinese ministry of commerce posted back in 2015 that, the amount of battery capacity used by biggest Chinese EV makers alone (excluding PHEW manufacturers) was 16.9GWh. And the amount of battery sales to car makers make less than 10% of the market in China.

I don't think the "EV" numbers are comparable to "car" numbers in China. Electric scooters and rickshaws are extremely popular there (and have a much larger fraction of their market segments than electric cars).

Source: traveling in big cities and tourist areas.

Post reply on HN