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Goldman Sachs invests $250M in compressed air energy storage

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Re: Goldman Sachs invests $250M in compressed air energy storage

#91

Post by rdtwo »

karmakaze wrote: post #51
slingnow wrote: post #41

Earlier quoted context omitted.

Can you name a method of large scale energy storage that isn't dangerous if done incorrectly?

I think the comment is more about being easy to do incorrectly/dangerously. Pumping water up into a reservoir seems easier/safer.

Yeah a large pressure vessel is basically a bomb. No matter how many layers of protection you add on the technology always wants to go too a rapid critical failure. Using statistics and layers of protection you can always show it to be safe to handle anything but when you get to such low probability your models be always be off and variables that you think are independent are actually linked (bad maintenance practices being one)

Re: Goldman Sachs invests $250M in compressed air energy storage

#92

Post by reincarnate0x14 »

fenixnuke wrote: post #69
ds wrote: post #38

Can someone explain their revenue to me? They claim 1m in revenue from their existing product which is: "1.75 megawatts (MW) of peak power output; a 2.2 MW charge rating; and 10+ megawatt-hours (MWh) of storage capacity" How does that equal 1m in revenue? You have to pay to charge your air-battery during low-cost hours and then discharge it during high cost hours to make the difference in revenue. The issue is, you c…

They are likely operating on the wholesale markets, which are market priced. For the western grid there is a significantly wider price range of prices. On peak days in the summer, prices can go up above $1,000/mwh in the late afternoon for several days. During the late fall/early spring, there are negative prices in the late morning (like $20-$50/mwh) due to extremely high solar production and low demand, so utilitie…

A lot of people look at these and think "that doesn't seem like it'd be remotely worth it for something that size" but it's really hard to explain just how badly California has painted itself into a corner on distant generation, huge variance between excess renewable capacity and peak load, and transmission congestion. The numbers don't make sense to people.

Pretty much all the solar plants we're putting in now have combined battery storage systems either for voltage support or "peaker" sales opportunities. In some places (like literal islands) it's about capacity smoothing or resilience, but the driving force behind all the investment is the US western interconnect with arbitrage opportunism starting to make real money and looking to make much, much more over the next decade.

If government-sachs is betting on this, they've probably got an even more pessimistic take on the CAISO market than I do.

Re: Goldman Sachs invests $250M in compressed air energy storage

#93

Post by cortesoft »

emptysongglass wrote: post #83
Raidion wrote: post #62

Earlier quoted context omitted.

This isn't correct. Deep mines are notoriously hot, because you're digging towards magma. Google says temps increase by 3° C for every 100m.

Naive question but couldn't our forerunners who otherwise succumbed to cold in harsher climates have exploited this fact to dig subterranean villages and towns? What's the element I'm missing as to why they didn't?

That it is really hard to dig down 100m without modern digging equipment.

Re: Goldman Sachs invests $250M in compressed air energy storage

#94

Post by benreesman »

JohnL4 wrote: post #53
tikkabhuna wrote: post #22

Earlier quoted context omitted.

Totally out of my depth here, but does cooling the gas down have the added benefit that it'll be heated by the earth whilst stored?

I'm guessing not. Earth's heat is way lower down. Think of a cave: always cold. I think what's going on is they're taking the heat out and storing it more efficiently than just dumping it down the ground, where (1) it would leak away, representing energy loss, and (2) as it leaks away, the air would lose pressure. (It would leak away b/c it's harder to insulate an entire mine, basically.) So, they pull it out ahead o…

This comment is an example of why I’ve become skeptical of the downvote button. It sounds like people read it, knew better, and politely pointed out that it was incorrect.

Everyone who might have shared the same misapprehension learned something and the parent wasn’t being an asshole.

Doesn’t that add to the discussion?

Re: Goldman Sachs invests $250M in compressed air energy storage

#95

Post by usrusr »

tristor wrote: post #80
themanmaran wrote: post #77

Earlier quoted context omitted.

On that note do you have a good explanation for why the air needs to be reheated? I didn't quite understand that from the video.

Air pressure is strongly correlated to temperature. Cooling the air after compression reduces pumping effort during storage, reheating it increases turbine head pressure during generation.

In other words: gas compression storage suffers from temperature losses. The compressed gas is hot, the heat dissipates from storage and that energy won't be coming back.

But if you extract that heat during compression you can put in a separate storage, one that is much easier to insulate than the compression tanks, and "mix it back in" during recompression, avoiding a large part of those losses.

Re: Goldman Sachs invests $250M in compressed air energy storage

#96

Post by buryat »

keewee7 wrote: post #12
nkurz wrote: post #7

Interesting. There's a good video describing the operation here: https://www.youtube.com/watch?v=cOWjwwKSR78 After watching it, I now understand that they aren't flooding the entire borehole, but rather are building a smaller high-pressure chamber at the bottom. The chamber is connected to pipes to a surface reservoir. When air is pumped into the chamber, it displaces water up toward the surface. When generating, the…

What goes into building and burying large scale underground structures like those air caverns?

you don't have to build those caverns as they already exist and we have extracted gas and liquids from them, also the volume should be already known as we know how much we pumped out (unless it's an old site)

Re: Goldman Sachs invests $250M in compressed air energy storage

#97

Post by [deleted] »

laputan_machine wrote: post #48
nkurz wrote: post #7

Interesting. There's a good video describing the operation here: https://www.youtube.com/watch?v=cOWjwwKSR78 After watching it, I now understand that they aren't flooding the entire borehole, but rather are building a smaller high-pressure chamber at the bottom. The chamber is connected to pipes to a surface reservoir. When air is pumped into the chamber, it displaces water up toward the surface. When generating, the…

The big question is how on earth are they digging out these caverns? That seems like a huge challenge, given that they're so far underground. Everything else seems relatively straightforward

[deleted]

Re: Goldman Sachs invests $250M in compressed air energy storage

#98

Post by reincarnate0x14 »

Murkin wrote: post #70

Can someone explain why this is better than just using pumps to pump water up from the reservoir and extract the energy with when the water returned back?

It's not, but it doesn't require a giant reservoir next to a 100m+ elevation change. Almost all of the really good locations for dams already have them, and their water discharge rates are driven by a lot more than just power generation.

Re: Goldman Sachs invests $250M in compressed air energy storage

#99

Post by buryat »

epistasis wrote: post #67

Grid storage is going to be big business in the future, on the order of size of storage for electrical vehicles. (And these will certainly not be mutually exclusive markets! Vehicle to grid tech will become widespread, as is already seen in the new F150 Lightning truck). Lithium ion will dominate for the foreseeable future, as the industry has scaled to massive sizes and already, and has the advantage of being curren…

> Grid storage is going to be big business in the future

it's already a big business

Re: Goldman Sachs invests $250M in compressed air energy storage

#100

Post by 2OEH8eoCRo0 »

lbriner wrote: post #89
2OEH8eoCRo0 wrote: post #68

Has anybody considered building flywheels into each wind turbine?

I'm not sure how that would help? If you had a flywheel and you didn't need the energy, what do you do with it? At least without a flywheel, you can easily stop the turbine. Also, any flywheel that would add significant difference would probably weigh hundreds of tonnes, which would make construction massively more expensive and difficult.

If you don't need the energy you just let the flywheel spin freely. It's a mechanical battery. I agree with your second point though- it would add considerable mass to the hub assembly of the wind turbine and there is no clear way to transmit the mechanical energy to ground level.
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