Goldman Sachs invests $250M in compressed air energy storage

https://www.canarymedia.com/articles/long-duration-energy-storage/goldman-sachs-just-made-a-record-setting-investment-in-long-duration-energy-storage

by rwmj • 5 years ago

258 310 5 years ago

canarymedia.com

ccvannorman• 5 years ago

I knew Danielle Fong from Lightsail Energy, folded in 2016, and at that time compressed air seemed like a great solution especially for LatAm that needed robust low cost batteries for critical infrastructure (like hospitals) on an unreliable power grid. https://en.wikipedia.org/wiki/Danielle_Fong

Would be great to see this technology reach maturity!

mikeyouse• 5 years ago

She's on HN, curious what her thoughts are: https://news.ycombinator.com/user?id=DaniFong

DaniFong• 5 years ago

https://twitter.com/DanielleFong/status/1481339424730497025?...

KennyBlanken3• 5 years ago

That wikipedia page answers everything you need to know about compressed air energy storage.

In 2018, the tech couldn't compete against lithium ion, and the price of lithium ion continues to fall 10-20% per year.

Compressed air and that concrete-block-stacking nonsense that keeps getting press are just magnets for uneducated investors.

PaulDavisThe1st2• 5 years ago

That wikipedia page says:

Compared to traditional batteries, CAES systems can store energy for longer periods of time and have less upkeep.

Sometimes the cost per MW/hr or equivalent is not the only metric worth thinking about.

eMGm4D0zgUAVXc7• 5 years ago

What is the expected efficiency of this?

rikkipitt• 5 years ago

I too was wondering that as the ideal gas law states that PV = nRT. When you compress a gas it gets hotter, conversely, allowing it to decompress cools it. I assume they store the heat energy...

https://en.wikipedia.org/wiki/Compressed-air_energy_storage

Mvandenbergh• 5 years ago

Yes, their website says they have a thermal store.

dragontamer• 5 years ago

CAES has lower efficiency, probably closer to 70% and only if you use something to reheat the air. (Compressed air loses temperature and needs an external source of heat to restore it to full volume)

Even if you use natural gas as a reheating element, the compressed air stores a significant amount of energy and is doing the majority of the work.

konschubert2• 5 years ago

What matters is efficiency per dollar:

Efficiency / cost

I am worried that the cost is the driving factor here...

EricE11• 5 years ago

If you ignore efficiency then you stop making a profit pretty quickly. You can solely focus all you want on cost; sooner or later efficiency will make you pay.

Goldman wouldn't be making that kind of an investment if they didn't have a handle on both parts of the equation. Indeed efficiency (dealing with losses from seepage) have been the nut that hasn't been cracked with compressed air storage; these guys seem to have an economical (efficient) way to deal with that problem. If true, then they really are worthy of Goldman's investment.

0898• 5 years ago

This brings to mind the other post about the Amish that's on today's front page. I believe the Amish sometimes use compressed air as an alternative form of power.

wongarsu• 5 years ago

Also quite popular in mines because it doesn't create sparks.

MisterTea2• 5 years ago

I read an article in a woodworking magazine about how one Amish woodworking shop was built to avoid using electricity. The whole shop ran off a stationary diesel engine driving a shaft in a floor trench and belt drove the larger stationary machinery like band saws, table saws, planers, drill presses, joiners and so on. But what about hand tools? A large belt driven air compressor off the diesel engine handled a myriad of air power tools like drills, orbital sanders, buffers and all that. Really neat setup.

lostapathy2• 5 years ago

Also adds a ton of pollution from using (often old and poorly maintained) Diesel engines in the name of avoiding the electric grid. Adding to that, compressed air is a much less efficient source of power than using electricity directly.

blincoln• 5 years ago

My father once told me that a lot of machine shops used to be set up that way, except that the powered shaft ran along the ceiling instead of in a floor trench. "Just throw a belt up over the shaft" and attach it to the machine you want to use, was how he described it.

I don't know if it's still there, but there used to be a fancy restaurant in the Eastlake part of Seattle that had started out that way, and still had the old Art Deco-ish drive shaft running around the ceiling. It was a neat touch point when I saw it and remembered my dad's description from years before.

bobsmooth• 5 years ago

I thought the whole schtick of the Amish was that they don't allow themselves to become reliant on technology, electricity just being an example. I doubt that Amish guy knows how to rebuild that engine should it fail.

noselasd• 5 years ago

This is basically how most indistrial setups was before engines and motors became a commodity. You had water wheels as your main power source, from which other tools was driven via belts and gears.

Later the waterwheel was replaced by an electric motor or a fuel powered engine - but still built around just one source of power, with elaborate setups to drive different tools. With the added benefits you could build factories and workshops outside main water sources.

nkurz7• 5 years ago

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 water flows back into the subsurface chambers, forcing out the high pressured air.

keewee7• 5 years ago

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

mschuster91• 5 years ago

Not much, technologically this is a conventional mine project, only that you mine air volume instead of rock and have to take care of the cavern being reasonably airtight afterwards.

buryat8• 5 years ago

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)

mirekrusin2• 5 years ago

I wonder what is the loss/recovery %age.

epistasis8• 5 years ago

I don't have specific numbers, but in other batteries of this type, the length of storage time before discharge affects the efficiency. Heat stored from compression is lost over time.

tikkabhuna• 5 years ago

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?

notatoad• 5 years ago

what would be the benefit to it being heated by the earth during storage?

all the temperature management here looks to just be counteracting the temperature changes that naturally occur when you compress or expand a gas. i imagine if you compressed it and then pumped hot air into water-filled caverns you'd get some negative effects of thermal shock.

JohnL43• 5 years ago

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 of time and put it back in when they decompress the air (which I think would add pressure back in due to heating a gas and maybe reduce problems caused by super-chilling other plant hardware? Anyway, seems fitting to add back what you took out if you're shooting for a closed system.)

laputan_machine• 5 years ago

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

rplnt2• 5 years ago

It says repurposing old mining operations. Not sure how feasible that is.

buryat8• 5 years ago

lots of mining caverns already had pressurized gas that was extracted, so those caverns are pretty tight to pump back some air

crunchyfrog• 5 years ago

Shaft mining is often used to reach underground deposits of iron, coal, etc. I believe they'd use the same process here.

sauwan2• 5 years ago

Is the voice in that video AI generated?

flyinghamster2• 5 years ago

A similar thing is done for natural gas storage. A well will be drilled into a rock dome that lies atop a layer of saltwater-saturated sandstone. Gas is then pumped into it, displacing the water, and then can be withdrawn later.

A report from 1961: https://www.ideals.illinois.edu/bitstream/handle/2142/42910/...

reedf1• 5 years ago

Given it's GS, $250m is peanuts.

woofcat• 5 years ago

I see that you've been down-voted however they have 40 billion in assets under management.

WHA8m• 5 years ago

I didn't dv, but that'd be .63%. That's not peanuts I'd say...

1-more• 5 years ago

Goldman Sachs agreed and invested $250 million from its private equity division.

Maybe they're referring to Goldman Sachs Capital partners which has 39.9B[0] under management which means this is 0.62% of their portfolio. In a totally chalk and cheese comparison that would be having 200k in your 401k and taking a $1,250 position in a stock, which isn't nothing but is a pretty small bet, I agree. Curious though if I'm guessing the part of GS correctly; I have no idea how they're structured and just spent like three minutes searching.

[0] https://en.wikipedia.org/wiki/Goldman_Sachs_Capital_Partners

boringg5• 5 years ago

GS isn't known for their scientific prowess - signal that they believe there is money in large scale ESS. Not sure if it's validating the technology at all though. Compressed air has been around for a long time at this point.

objektif2• 5 years ago

Who is known for their scientific prowess? A16z and with sprawling investments in web3? Capital is capital. We should be cheering on these types of investments regardless. Electric motors have been around for a looong time as well..

boringg5• 5 years ago

The VC and investment world in energy technology is quite different then the A16z and traditional VC world or financial heavyweights.

Having had GS invest in companies in the energy tech space in the past and having not particularly great success - I wouldn't think this is a strong signal. More that the financial heavyweights think there is action and they want to get in.

buryat8• 5 years ago

the governments should invest instead i agree but it doesn't hurt if a private venture can help us all

axg11• 5 years ago

Does this technology only work in select places or are underground caverns fairly commonplace?

nkurz7• 5 years ago

Appropriate natural caverns do exist, but are not common. One of the main differentiating factor between this approach and others is that they drill a man-made borehole rather than depending on finding a pre-existing cavern.

throwawayboise3• 5 years ago

Near where I live there is a large underground natural gas storage field using natural caverns.

dylanz• 5 years ago

Is this similar to a trompe? https://en.m.wikipedia.org/wiki/Trompe

CarbonCycles• 5 years ago

This isn't new...I recall grad students working on this as far back as 2010.

Some citations from an article: “Bottled wind could be as constant as coal.” Wired Magazine. Retrieved 7/15/2010, 2010, from http://www.wired.com/wiredscience/2010/03/compressedair-plan... 59

Cavallo, A. (2005). Controllable and affordable utility-scale electricity from intermittent wind resources and compressed air energy storage (CAES). Science Direct.

rplnt2• 5 years ago

This isn't new...

Well, yeah, this is in the opening of the article:

It updates a long-standing technology that never took off for electrical storage.

There is/was plant operational since 1970s in Germany[1], which looks similar to the Wired article, but different from some other solutions posted in comments. Missing some parts perhaps to be viable.

1. PDF: http://www.fze.uni-saarland.de/AKE_Archiv/AKE2003H/AKE2003H_...

belorn2• 5 years ago

How does the economics of this look like, and how do they intended to get back the investment. If its to buy low when wind/solar production is high and sell when production is low, what will the cost per watt be? If its subsidies, how much will this cost the government?

The article seem to mostly describe this as a technology project to test the technology at scale, but they do also mention profits. Is the basic premise of buy low sell high, exclusively on renewables, enough to offset the cost from energy conversion, building, staff and other costs, and if so, by what degree compared to other method to produce energy? When is it estimated to have paid its initial investment?

EricE11• 5 years ago

Energy storage if you want to rely solely on renewable energy sources is THE KEY to making that even remotely feasible.

Current solar and wind renewables are NOT predictable nor reliable for sustained power generation. With Coal, Natural Gas, Nuclear and Hydro you can generate power on demand, no matter what the environment is doing. Well, Hydro in the west is getting dicey with the drought - but even that is far more stable than wind/sun which can vary wildly week to week, day to day or even hour to hour.

That's why technology like this is so exciting. If you can look at the average production of a renewable over a month, then within a year the peak month, then look at the worst months, then have enough storage to cover a percentage of a peak month based off the hedge of the worst month then you are getting to a point where a solar farm isn't just an opportunistic source of power based on how much the sun is shining, but a reliable energy source that can be counted on whether the sun is shining or not.

Same for wind farms.

Energy storage is crucial if we seriously want to transition to renewables and hence the investment from Goldman Sachs.

If this company is even remotely successful in actually delivering then $250M is a pittance to what they will receive back in the long term.

There are also a lot of unused/abandoned underground structures - from various wells that are now dry of the resource they were originally drilled for to mines that are no longer productive. The problem has been sealing them from seepage so you don't loose your stored air - this article was light on details but that seems to be this companies claim to fame. They seem to have found economical ways to deal with those issues - enough to convince the boffins at Goldman Sachs they are worthy of investment. I guarantee you Goldman is not just tossing out money willy-nilley without performing some significant due diligence!

belorn2• 5 years ago

The question is still economics. At minimum the cost per watt/h need to be cheaper than to build a nuclear plant and have it run when demand exceed supply from renewables. Is this true for compressed air?

When people discuss green hydro as a storage solution the numbers so far, from what I have managed to interpret, is around 3-5 times that off nuclear for the same amount of energy delivered. It is still technically possible to make a profit given enough subsidies and time, and it get much more economically if the hydrogen can be used directly in the production chain like steel and fertilizer. Right now there are a steel foundry in Sweden testing the technology and economics doing that, through I don't know how much subsidies and tax reductions were involved.

Which all means the question about economics remains. There are many alternatives to fossil fuels but the primary question everyone debates is the issue of price. Without a price per watt/h or a time frame for when the investment get repaid its impossible to separate the practical from impractical, and the subsidy question is very relevant when discussing this on a national level.

Giorgi• 5 years ago

I really enjoy learning about quirky ways to "store" energy, there is also one case that allows "storing" of energy by pushing massive concrete blocks uphill and when energy is needed, blocks simply slide down and generate energy. Not sure if this can be called "Storing" though.

konschubert2• 5 years ago

The more efficient version of this idea looks like this:

https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...

s1artibartfast3• 5 years ago

I don't know that this is always the case. I think that solid mass gravity storage projects have quite high efficiency.

there is no rule that water+ turbines is more efficiency than Solid mass + alternators.

EricE11• 5 years ago

It's only efficient if you have the right environment for it to work (enough space, enough of an elevation gradient, etc.).

If you can't build it where you need it, then efficiency doesn't really matter now, does it?

terpimost• 5 years ago

Interesting, I guess the water freeze isn’t a problem in those places

RyEgswuCsn• 5 years ago

I was wondering the same. Although they can somewhat mitigate that by adding some antifreeze additives to the water perhaps?

jesperlang• 5 years ago

There is a great post on compressed air energy storage (CAES) over at Low-Tech Magazine:

https://www.lowtechmagazine.com/2018/05/history-and-future-o...

tomcooks• 5 years ago

Finally someone mentioning this, it's a gem of an article in a gem of a website

smoyer• 5 years ago

Curiously there's a second article discussing compressed air energy on the front-page of Hacker News at the moment - it's about the Amish and their hacker mentality [0]. There's a beautiful discontinuity between one of the more tech-savvy old-guard banks and the technology-careful Amish adopting the same technology.

0. https://news.ycombinator.com/item?id=29905288

gjvc• 5 years ago

"Workers descend to hollow out a cavity, which the company then floods."

reminiscent of The Day Today https://www.youtube.com/watch?v=eTGE9153VFE

ds3• 5 years ago

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 can buy 2 megawatts of power 24/7 at average datacenter energy pricing (~5c/kwh) for $2400/day or 876k/year. Who is paying more than that for less energy and only at certain hours?

Is there some energy company somewhere that sells power during the day at like 50c/kwh and 1c/kwh at night???

323• 5 years ago

While I don't know about their numbers, having a "grid level battery" is definitely something people (or gov subsidies) will pay for.

_delirium• 5 years ago

These kinds of utility-run storage facilities usually buy and sell on the wholesale spot market, which swings much more than retail prices do. Somewhat similar economics to gas "peaker" plants, which only fire up when supply is tight and prices spike, making it economical to run a higher-cost generator.

The Hydrostor plant is in Ontario. Here's an archive of hourly spot-market electricity prices there (in dollars per MWh): http://reports.ieso.ca/public/PriceHOEPPredispOR/. So far in 2022, prices have been as low as $0.00/MWh (during a few hours overnight on Jan 5) and as high as $230.87/MWh (during the morning of Jan 11). In 2021, hourly average prices even exceeded $1000/MWh ($1/kWh) twice, on March 28 and October 10.

ds3• 5 years ago

I would need to see the math, because nothing adds up to even 1/10th of their claimed revenue. Best case, they bought 10mwh on jan 5th and sold it at the perfect time on jan 11th. This would give them 2k in revenue in 6 days.

Wheres the rest? And what about if you cant nostradamus predict the best times to buy and sell?

s1artibartfast3• 5 years ago

Still seems extreme. IF my math is right, they would need to buy and sell 10MWh every day at a 27c/KWh markup. Given they they deliver at ~2.2 MW, This means that they would have to hit this markup for a 4 hour duration, every day.

fenixnuke3• 5 years ago

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 utilities are literally paying you to use electricity. It's not inconceivable to get to $1 million a year on 1 mwh of storage.

Take a look at the price maps and historical pricing data if you are curious https://www.caiso.com/todaysoutlook/Pages/prices.html

ds3• 5 years ago

Im familiar with energy markets. Im also familiar with the fact that any serious seller or buyer of energy locks in yearly pricing contracts and is unaffected by these swings. Any serious datacenter or industrial buyer is not relying on spot pricing. These energy markets also dont exist in every state.

reincarnate0x142• 5 years ago

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.

samstave5• 5 years ago

How can you make a storage system that only slurps power off of another grid that "literally pays you to use electricity"? during those times?

s1artibartfast3• 5 years ago

I agree it does seem like a stretch.

IF 10MWh is their daily cycle, they are selling 3,650,000 kWh/year. To hit $1M per year, they would need to be selling ~27c/KWh above their buying price.

I get that you can have a big spread if you are being paid to take power, and paid again to sell it.

thehappypm3• 5 years ago

I think that’s it basically. New England consumers pay ~$.22/kWh. We’re going to have offshore wind energy in the next decade that might conceivably have surplus power quite a lot. It’s not beyond the realm of possibility that these plants could have a deal with the power plants to take extra power for free so long as they have guarantees on filling the expected gaps or meeting expected spikes in usage. Everyone wins.

rdtwo3• 5 years ago

In the 80s my grandfather used to do this for the former Soviet Union. Long story short they were pressuring a salt mine at night for energy storage and somebody failed to report a water leak during the day. They tried to depressurize the mine but it ended up blowing up anyway killing a couple people in The process. This shit can be really dangerous if done incorrectly.

slingnow• 5 years ago

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

karmakaze2• 5 years ago

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

faeyanpiraat• 5 years ago

How did the situation go from a water leak to an explosion?

alan-crowe• 5 years ago

The Lake Peigneur Drilling Accident is a tale of water getting into a salt mine from the lake above, due to drilling for oil in the wrong place. As the water dissolved the salt, the hole grew bigger and bigger, exponentially. The lake emptied into the salt mine, turning it into brine.

https://en.wikipedia.org/wiki/Lake_Peigneur

So I'm picturing water leaking into a salt mine full of pressurized air. Naively it makes a hole, and a hole is just a leak. But if the water starts dissolving the salt in a process that runs away, then it is more like popping a balloon, but on a grand scale.

photochemsyn• 5 years ago

It's probably some kind of hedge strategy for energy crises like the recent Texas disaster (which appears to have been very profitable for GS [1]). Having this capacity around when other sources go down means they'll be able to provide power in similar situations and so reap massive profits. Climate chaos == $$$ I guess.

Bloomberg March 5, 2021
Goldman Sachs Group Inc. could gain more than $200 million from the physical sale of power and natural gas and from financial hedges after spot prices surged across much of the U.S., according to people with knowledge of the matter. Morgan Stanley’s gains could come in under $200 million, according to a person with familiar with the matter, and Bank of America Corp. stands to rake in profits as well...
The historic cold that battered the central U.S. last month led to sweeping blackouts as ice formed on wind turbines and pipelines froze, forcing oil and gas wells to shut. As traders and power suppliers struggled to find fuel to meet obligations, prices skyrocketed. In Oklahoma, gas traded at more than 300 times normal levels, while electricity in Texas surged to $9,000 per megawatt-hour.

Full article: [1] https://www.investorvillage.com/smbd.asp?mb=5028&mn=126049&p...

qeternity• 5 years ago

Having this capacity around when other sources go down means they'll be able to provide power in similar situations and so reap massive profits. Climate chaos == $$$ I guess.

I understand that people don't like when others profit from a crisis, but this is also how we solve these problems. Having more generation capacity than we otherwise would have is a good thing, even if Goldman make money on the back of it.

I'm not arguing there isn't more to be done, but when people say "greed is good" this is what they mean.

_xnmw• 5 years ago

This is where capitalism goes off the rails. Instead of investing $250m into making the power grid more secure and reliable, they choose to invest in profiting off disaster.

jvanderbot• 5 years ago

providing instant-on, scalable energy capacity to the grid is both potentially profiting off disaster and investing 250m into making the grid more reliable and secure.

epistasis8• 5 years ago

You are sorely mistaken, this sort of battery is exactly what makes the grid more reliable and secure. Especially on grids like Texas, which have massive amounts of renewables.

Batteries are the Swiss Army knife of the grid, they can fix all sorts of problems, from inadequate transmission capacity, to frequency regulations, to peaking needs.

EricE11• 5 years ago

As others said, energy storage technology is going to be the only thing that makes renewable energy more than a curiosity. Renewable energy is neither reliable nor predictable which is why it can not replace base load requirements.

However, if we had sufficient energy storage capacity, they we could indeed fully transition to renewable energy once and for all!

throw1234651234• 5 years ago

Heh. This ties in with the "Amish Hackers" article here: https://news.ycombinator.com/item?id=29905288, which states that the Amish use compressed air to store electricity.

nemacol2• 5 years ago

I would like more detail on the "Thermal management system" and how long it could store the heat it captures.

One of the benefits they touting is "Long duration energy storage" I would think the limiting factor would be the ability of the thermal management system to retain the energy it captured to reheat the compressed air. Am I thinking about this correctly?

themanmaran• 5 years ago

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.

tristor3• 5 years ago

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.

nemacol2• 5 years ago

Warm air takes up more space. If you cool it before pumping it into the ground you will not waste time/energy. If you pump warm air down it will lose heat into the ground and shrink and you would lose capacity - pumping that last x% the tanks will be fuller until they cool down.

You warm up the air on the way out to expand it and you get more air to spin the turbine. More bang for your buck.

I believe is the thinking.

usrusr4• 5 years ago

To the best of my knowledge that thinking is spot on.

A possible component that might be missing (in the thinking and/or in the proposed implementation): the stored heat could also be utilised separately if needed, so if you have an intermittent heat consumer and an intermittent electricity consumer you could consume the heat first, then leave the remaining compression energy (what you could recover without reheating) "forever". Bonus points if you also happen to have a coolant consumer to benefit from the temperature delta caused heat loss or premature heat consumption.

samstave5• 5 years ago

After seeing videos of lava pouring into the ocean I have fantasized about a power generation system:

Artificial geo-thermal power gen:

Dig a deep enough hole but near the ocean, and let ocean water pour into the hole that gets close enough to magma such that the magma creates a steam blast back out a tube with a bunch of turbines to spin.

danans4• 5 years ago

One of the benefits they touting is "Long duration energy storage"

According to their marketing video [1] "Long duration" is relative to current lithium ion battery-based storage. So their system can store energy up to 24 hours vs a few hours for batteries.

For even longer term storage (weeks, months, seasons), some time of chemical storage will be needed. Currently, both hydrogen electrolysis and ammonia synthesis [2] are being explored for that.

1. https://youtu.be/cOWjwwKSR78?t=136

2. https://www.youtube.com/watch?v=5Y_2Z_VwFNc

aaron695• 5 years ago

It will be fake

But Goldman Sachs can blow their money however they wish. Although no doubt governments will also throw bad money into this, but I guess if people want their government to fake their lives, so be it. It seems that's living in The Jetsons future HN idolises.

Why it is fake - "Why is adiabatic compressed air energy storage yet to become a viable energy storage option?" - https://www.cell.com/iscience/pdf/S2589-0042(21)00408-9.pdf

The Australian project has no go ahead -

Hydrostor seeks clarity over compressed air-energy storage facility in Broken Hill - https://www.abc.net.au/news/2022-01-12/hyrdostor-seeks-clari...

And yes as part of this fake world, Goldman Sachs has not put 250M into this company, it's in tranches. Fake worlds built on top of fake worlds.

PBnFlash3• 5 years ago

Air is kind of a shitty working fluid. I always kind of dismiss compressed air storage because of that.

I saw a video recently that pumped water into tanks and used used the air as a spring. Just dip a pipe down and use the air to move the water. Extracting energy from a hyrdo generator.

https://youtu.be/sBF5EnK9MPs

u320• 5 years ago

Isn't that just pumped hydro? You would need similar masses of water.

PBnFlash3• 5 years ago

I imagine it will get better performance from high pressure water instead of the few psi of a small elevation change.

ted_dunning2• 5 years ago

It is pumped hydro, but you don't have the same mass of water because of the dramatically different pressures involved. Smaller water mass is the advantage to this, but the problem of managing heat is the downside that pumped storage doesn't face.

This general technique is known as "liquid piston".

epistasis8• 5 years ago

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 currently unstoppable in the EV space.

Batteries with a design that can decouple the energy from the power ratings, like this one, will be able to address parts of the market that lithium ion cannot. And if the cost per MWh of additional energy is cheap, and round trip efficiency stays above 50% or so, that sort of battery will have a huge edge in a part of the market that currently has no clear winners.

There are many competitors in the non-lithium ion storage space, but one of the top contenders to watch is Form energy, which has a rust-based battery, and is rumored to have a cost as low as $20/MWh, about a tenth of that of lithium ion.

octo_t• 5 years ago

Seems like everyone wants to make everything in Rust these days! /s

KennyBlanken3• 5 years ago

one of the top contenders to watch is Form energy, which has a rust-based battery.

Form is still in the cell prototyping stage, as best I can tell - maybe not even that. There's zero information on their website about where they are in the development process or really anything substantial about their design.

ESS on the other hand has a design they've had out testing in the field for a couple years ( https://essinc.com/ess-inc-to-deliver-two-energy-warehouse-s... is one such location) and has been shipping actual product: https://www.businesswire.com/news/home/20211115006337/en/ESS... and they've been pretty open about their design, though some of their old whitepapers have been removed from the site.

Competition in the market is certainly a good thing, but Form needs to do more than just have a shiny website, a screengrab of a zoom employee meeting, and a blog with 'industry insight' posts (because they have nothing to show for tech/product.)

epistasis8• 5 years ago

Agreed that Form has lots of hype, but that's one thing that can be needed in addition to working tech. Utility decision makers are not the best at adding new tech to the grid or dealing with innovation. Having some big industry names and the support of the business press that the utility execs and shareholders read is it's own form of currency when dealing with such archaic businesses.

buryat8• 5 years ago

Grid storage is going to be big business in the future

it's already a big business

samstave5• 5 years ago

Isn't Afghanistan known to be sitting on top of ~1 trillion$ worth of lithium, and also Bolivia?

czbond• 5 years ago

I still believe that's why the U.S. invaded anyway. We didn't care about overtaking a country for some silly resistance leader. You do it for big money to bilk - like Iraq and oil.

EricE11• 5 years ago

Lithium Ion is not sustainable for the long term - we have neither the materials nor the manufacturing to not only keep up what would be required for full scale car and grid uses, but don't forget Lithium Ion batteries have a finite lifespan and need to be replaced. The more you put into service, the more you have to manufacture beyond just the batteries needed for new requirements.

epistasis8• 5 years ago

I'm not sure that your predictions will hold here. More lithium is discovered as demand grows, and there have been huge additions to known reserves in just the past few years. Looking at current numbers and saying "that's it" is clearly wrong, and given its overall abundance and lack of demand until now, it's a really strong prediction to say that we won't have enough for at least 500TWh of storage, if not more.

Manufacturing capacity is expected to increase 10x every five years, with roughly 20-30TWh/year production in 2031. I can't think of any fundamental constraints there, could you specify why that can't increase?

Lithium recycling is being planned by nearly all manufacturers and many countries will mandate it. If lithium supplies are short, recycling will be highly profitable. If lithium is super abundant, recycling may be more expensive than recycling, and a program like what we currently use for lead acid batteries might be needed for a circular economy. But the fundamental point is that end of life for the battery does not mean that the lithium is gone, it's not a fuel.

How did you collect this odd set of concerns? Did you think of them or did you find them in the media somewhere?

Melatonic6• 5 years ago

I have been saying for years that we should have a windmill system you could place on top of a building or home that powers a larger, highspeed flywheel buried underground below the house. Ideally with the flywheel in vacuum and balanced by magnets for reduced friction. This ensures no loss converting energy types (mechanical to mechanical) and it can be used later for electricity or other energy in small, large bursts (sort of like a capacitor). You would still want batteries for energy storage but this would drastically increase the lifespan of those batteries by reducing stress on their chemistry. Batteries really do not like to discharge in short, high intensity bursts. There are flywheel based UPS systems that work sort of in a similar principle and they have much longer maintenance intervals vs a battery type UPS>

epistasis8• 5 years ago

I think both battery and solar tech has advanced to the point that solar plus batteries undercut a lot of grid supplied energy in costs.

Or at least it would, if the overhead for current solar installers wasn't so high. Retail prices for equipment are incredibly low, but the boom-and-bust cycle caused by uncertain regulatory terrain ends up requiring successful biz to have massive marketing costs, which results in really high prices overall.

mispell• 5 years ago

That's already a thing. Kodiak AK has one which coupled with wind turbines enabled the town to go to 99% renewable electricity. https://www.hitachienergy.com/us/en/references/grid-edge-sol...

2OEH8eoCRo03• 5 years ago

Has anybody considered building flywheels into each wind turbine?

lbriner• 5 years ago

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.

2OEH8eoCRo03• 5 years ago

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.

buryat8• 5 years ago

flywheels storing a lot of energy are very dangerous, if something happens it's a flying thing that destroys everything on its way

2OEH8eoCRo03• 5 years ago

Like a giant rotating wind turbine?

toss16• 5 years ago

Interesting question, but seems unlikely.

If you're thinking of a direct mechanical linkage, you wouldn't want to put it up on the tower because the mass to effectively store megawatt-scale power is way more than you'd want to support up high. Also, since the wind blade usually swivels to the wind, you'd want to avoid the rotational inertia. So, you'd need a mechanical linkage to transmit the power to the ground, maybe installing it under the tower base.

You would not want to use a direct mechanical attachment, i.e., resembling a combustion engine - transmission flywheel, because this would impair the ability of the wind turbine to start. Generally, turbines are designed for minimum inertia to easily start in low-wind conditions. A direct connection would impede that.

Now, we're adding a clutch-sort of mechanism, and that has its own additional complexity, weight, and energy.

Moreover, considering that we're trying to store megawatt-scale energies, we are at a large mass spinning very fast, and probably spun up with an electric motor.

So, it would seem the best way to do that would be to make a flywheel farm, with the flywheels below ground to contain failures. At this point, why locate it in the probably inconvenient location where the wind turbines are located, and instead put it somewhere more convenient, such as nearer to the consumption areas?

Murkin4• 5 years ago

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?

tristor3• 5 years ago

It requires less surface area, both due to compressibility and due to hydrodynamics. Additionally, water is a strong erosion source, air is not, so this can make use of existing excavations much easier and deep excavation is very very expensive.

Murkin4• 5 years ago

But they already fill the underground containers with water when there is low air pressure. (thats what the reservoir on top is, no?)

hannob2• 5 years ago

Pumped water only works if you have the right conditions. I.e. you need a certain altitude difference and enough space to have an upper and a lower water storage facility.

Pumped water storage is very efficient and an established technology, so when it's possible it's a good choice, but it's not possible everywhere.

Murkin4• 5 years ago

From what I gather in their explanation, they use air pressure to push water out of an underground container.

The energy is reclaimed when the pressure is released (i.e. water can fall back and fill the container).

How is the energy density different that what is provided by the water's static energy due to gravity?

reincarnate0x142• 5 years ago

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.

buryat8• 5 years ago

not a lot of places have enough terrain to create a lake, plus in some places there's already shortage of water so removing it from usage would be pretty bad

Murkin4• 5 years ago

They have a large water reservour in their plan..

hannob2• 5 years ago

Interesting.

The German energy company RWE has announced a while ago that they want to build a compressed air storage facility. However the project went nowhere and was silently buried at some point.

EricE11• 5 years ago

Preventing air leakage is frightfully hard - air molecules are a lot smaller than liquid molecules :)

  Apparently these guys have found an economical way to deal with it.  If true then I can easily see why Goldman jumped on them.

AlexTWithBeard3• 5 years ago

In early 20th century in London there was an alternative hydraulic "power grid" with plants (aka pumps), storages and an underground distribution network of pipes. A building, for example, could connect to high pressure water mains and use it to power elevators. Electricity eventually won, but it's interesting to see an idea coming back.

Zeppelins next!

[1] https://en.wikipedia.org/wiki/London_Hydraulic_Power_Company

samstave5• 5 years ago

There also used to be "central turbines" whereby there was a central spinning rod that one could attach belts to in order to spin a thing to get work out of it...

called line and shaft

https://www.youtube.com/watch?v=7qt5tltnvF8

cjrp• 5 years ago

Really cool, sort of like how an ICE drives ancillaries

snalty• 5 years ago

There's a cool working example of this at Kelham Island Museum in Sheffield, England.

DrBoring• 5 years ago

I once saw this in use at a restaurant to drive ceiling fans. I looked up some videos:

https://www.youtube.com/watch?v=y-uCvwEq3co

https://youtu.be/1IWTM1rNCnw?t=78

Someone• 5 years ago

That was normal in the age of steam. Having lots of tiny steam engines on the factory floor does not make sense. Keeping them running is too labor intensive, they would be fire risks, and they’re less efficient.

Smoosh• 5 years ago

And a similar system used to be common for shearing: https://www.sheepcentral.com/wool-growers-support-call-to-ph...

_pmf_• 5 years ago

The Amish use compressed air: http://www.amishfamilyvalues.com/amish/amish-electricity/

caseyohara• 5 years ago

This is interesting:

"This was a crisis. Without electricity, the Amish couldn’t store milk, and the church was adamant that Amish were not going connect to the local electric company. Finally a solution was found. It was decided that diesel generators could be used to power the refrigerators. This decision allowed the Amish to continue their tradition as dairy farmers without having to use public electricity."

So the Amish are allowed to use electricity, just not from the public grid? Generators seem like a weird loophole to their own rules.

javajosh2• 5 years ago

Zeppelins with modern materials and technology would be very, very cool. I'd ride in one.

xwdv• 5 years ago

What would be even cooler is zeppelins with swimming pools and jacuzzis while you take in the views of the sky.

Melatonic6• 5 years ago

The military is actually doing a ton of work with blimp and zeppelin like things currently - you do not hear about it much but there is a a ton of testing and research being done.

freefal• 5 years ago

A bit tangential, but New York City has an operating steam system that's still widely used by commercial customers.

https://en.wikipedia.org/wiki/New_York_City_steam_system

radicaldreamer• 5 years ago

San Francisco has one too, used primarily for heating buildings https://clearwaycommunityenergy.com/system_lists/energy-cent...

antupis• 5 years ago

District heating is pretty normal at northern Europe altought now we use mostly water.

dmix• 5 years ago

The interesting part of the NYC one is the scale

Today, Consolidated Edison operates the largest commercial steam system in the world (larger than the next nine combined).

Naga• 5 years ago

Downtown Ottawa has a similar steam system too, although I think it's mostly government buildings instead of private, commercial buildings that are hooked up to it.

wefarrell• 5 years ago

It is funny (if not terrifying) that we have literal geysers spring up on crowded city streets every once in a while.

JoeAltmaier• 5 years ago

The University of Iowa campus has a steam system under the campus, installed in the last century. Nowadays the steam is recovered waste from the electric plant. But it's still in use!

bumby3• 5 years ago

If you want to find good candidates for saving the campus tons of money, go to the roof of one of the tallest buildings on a cold day and look for the buildings that are venting lots of steam. They likely have a failed steam trap somewhere in the building. It's not uncommon for failed steam traps to save thousands of dollars a year apiece when fixed.

duxup• 5 years ago

University of Minnesota too, not long ago replaced their old boilers and main steam plant.

mabbo2• 5 years ago

This sort of system is used today in many modern industrial facilities. Case in point: Amazon warehouses.

Lots of the mechanical automations inside some of those warehouses are powered by compressed air in open loop systems. As the conveyor pushes the item off, onto a different lane, there's a distinct hiss of air escaping. The movement of the machine was powered by compressed air.

Out in the parking lot in these facilities, you'll see a huge compressed air tank (or many), constantly being refilled. Tubes from these go into the building like arteries in a body. Often inside the building there will be buffer tanks to help ensure constant pressure.

Source: worked for a few years with guys who maintained these systems. Some of what I learned may be wrong, so feel free to correct me.

throw8932894• 5 years ago

It is pretty common in regular workshops. Compressed air powers drills, riveting machines, sprays guns, jack hammers... Tools powered by compressed air are simpler (no electronics), more durable and cheaper.

bumby3• 5 years ago

They aren't really the same types of systems.

Pneumatic "muscle pressure" is common in lots of industrial applications, especially those that operate in austere environments. But those are different than the tech being researched in the article in large part because the mechanical compressors in industrial applications are hugely inefficient. Many constant volume compressors have 90%+ of the energy as waste heat.

I believe the article is referencing isobaric (constant pressure) compressed air energy storage (CAES) that have much better efficiencies.

enginoor• 5 years ago

The common term is "pneumatics" and the components are prevalent in all automation and manufacturing. The air required is typically compressed on site.

Pneumatic actuators are relatively inexpensive, have a binary state that is easy to control, and offer a high power density.

RickJWagner• 5 years ago

I saw a similar thing in a very old building, I think from the early 1900s.

The web of tubes was for messaging. (Just like some bank drive-ins work.) Users would put paper messages in capsules which were put into a pipe. Compressed air would carry the message to a central switching station, where human operators would re-route the message to the proper destination tube.

It was pretty cool, in a steam-punk sort of way.

adrianmonk• 5 years ago

That is an interesting system (which I had never heard of), but it seems pretty different from this.

The London system used water under pressure and was used for power distribution, whereas this one compresses air and is for energy storage.

And the Wikipedia article says the London system used "large vertical pistons" with weights to store energy, whereas this one pressurizes air.

MSFT_Edging• 5 years ago

There was an article on here earlier about Amish tech and they also make use of a lot of pneumatic machines for daily tasks.

IncRnd• 5 years ago

Hydraulic refers to liquid. Pneumatic refers to compressed air.

rcurry• 5 years ago

I once took a tour of the Mabel Tainter theater in Menomonie Wisconsin. The original light fixtures had been built to work off of both gas and electricity, just in case the whole newfangled electricity thing didn’t work out.

mderazon• 5 years ago

Isn't that the concept behind "streampunk" ?

https://en.m.wikipedia.org/wiki/Steampunk

MPSimmons• 5 years ago

That sounds dangerous.

sauwan2• 5 years ago

The round trip efficiencies for these compressed air storage have typically been terrible (<50%). That's mostly because compressing air is super inefficient (lots of wasted heat). Are they able to harness that waste heat in some productive way?

ETA: Just saw the video. Looks like they store the heat to boost generation on the return trip. This [1] says they get ~60% efficiency.

[1] https://www.inceptivemind.com/hydrostor-build-largest-compre...

arnaudsm• 5 years ago

60% is great! That's much better than hydrogen, but still far from lithium. Let's hope the $/kWh is decent.

danans4• 5 years ago

It's not quite lithium ion efficiency, but it serves a different duration energy storage market (up to 24 hours vs single hours for lithium ion battery storage), and it has a much longer service life (50 years), so the levelized cost of storage might be lower than lithium ion battery storage.

thehappypm3• 5 years ago

Especially when you consider that the use case here is surplus energy, like when the wind is blowing harder than can be consumed. Efficiency might not be so important if you’re buying free wind or solar energy, as long as it’s above some minimum threshold. 60% feels pretty good.

surfmike• 5 years ago

This made me wonder what happened with LightSail energy, and found this takedown: https://www.greentechmedia.com/squared/letter-from-sand-hill...

Compressed air still seems like a promising idea to help solve the scale of energy storage we need, so I’m happy to see more companies taking a crack at it.

ck2• 5 years ago

Why not use spare energy to lift -really- heavy object(s) and let gravity power the generators when there is a shortage?

Million tons of concrete isn't going to suffer any maintenance expenses over decades.

nkurz7• 5 years ago

That's a really popular idea on the internet because it's very easy to grasp, but the numbers don't work out well. The weights you can actually lift aren't much compared to the volume of a reservoir of water, and the heights you can lift them are but a fraction of the thousands of meters being discussed here. Yes, the concrete isn't going to require much maintenance, but the gearboxes needed are a significant engineering challenge. Pumping water or compressing air are a lot easier, and batteries are going to be hard to beat.

toss16• 5 years ago

Except it is already being done by multiple companies [0], Energy Vault in Switzerland [1], Gravitricity in Scotland [2], New Energy Lets go [3], and Gravity Power [4]. All have raised substantial funds and are building.

Sure, pumped hydro has advantages, but has serious geographic limitations - you need a fairly ideal site. The key is that these can be built almost anywhere.

[0] https://spectrum.ieee.org/gravity-energy-storage-will-show-i... [1] https://www.energyvault.com/ [2] https://www.gravitricity.com/#about [3] https://n-e-l-g.de/ [4] https://www.gravitypower.net/

escapecharacter• 5 years ago

Ah, FartTech

jl6• 5 years ago

I think the video said the system runs a cycle within a period of around 24 hours. What would it take to store energy in compressed air for ~6 months? This is what high-latitude dark-winter countries need: the ability to over-generate in the summer and draw down on stored energy in the winter.

marvin• 5 years ago

Pumped hydroelectric storage is an obvious choice for the countries that have the geography, in effect meaning that most of the infrastructure for doing it is already in place. Hydroelectric reservoirs allow storing energy more or less indefinitely.

Of course, the capacity will rarely have been dimensioned for keeping 6 months of usage on hand, but combining pumped storage with over-provisioned wind energy would allow for living through months of unfavorable sun, rain or wind conditions.

robomartin2• 5 years ago

Based on my reading, these systems are, at best, in the order of 60% efficient. To state the obvious, this means that fully 40% of the energy they pull from the grid will be wasted. Burned. Never to be recovered. How is that a good idea?

Solar? Well, solar isn't free energy. What's the comparison to grid scale batteries for storage? That process is far more favorable, with efficiency exceeding 80%.

I have to admit not understanding how this kind of an investment happens. I don't see this as viable technology at scale. We are far better off building nuclear power plants (talk about dense energy storage!).

Here's a good article on pumped thermal energy storage systems and how they compare to alternatives. The authors cover thermal storage in some detail.

https://www.frontiersin.org/articles/10.3389/fenrg.2020.0016...

EricE11• 5 years ago

You are spot on - the real answer is readily available: nuclear. We have reactor designs that if the active systems fail the reactors shut down naturally instead of running away. We have designs that can be burning all that "spent" fuel we are currently trying to bury for 10,000 years (!). Modular reactor designs in particular have incredible promise to provide for infinite scaling (just add more modules as needs increase), deal with the inefficient building, maintenance and decommissioning costs of todays light water reactor designs, and being modular provide far more granularity in power delivery further negating the need for energy storage to smooth out spikes and troughs in demands; allowing energy producers to far better match generation to power requirements.

Sadly I think it will be far more feasible to develop energy storage technologies than hope we can ever get enough people to be rational about nuclear. I mean how asinine is it for Germany to have turned off perfectly working and economically viable nuclear plants to then be dependent on RUSSIA for natural gas? How dumb do you have to be to be to think that's a REMOTELY good idea? Yet here we are (thankfully France seems to be far more rational - you don't hear them even suggesting they plan to be equally idiotic).

Many battery storage studies don't account for replacement/maintenance, or the infrastructure that would be required to sustain replacement/maintenance at grid scale, let alone the resources required to scale up to handle initial deployment of batteries in sufficient quantities to support the entire grid. Where are we going to get the manufacturing capacity, let alone materials? The scale here is pretty mind boggling if you start to do the math.

Our current battery tech is nothing more than a transitory technology - they are far from sustainable long term. Personally I think super capacitors will be our ultimate solution, but in the meantime if these guys really have dealt with the seepage issues of compressed air, this is are next best bet for MASS energy storage at scale. You only have the privilege of worrying about efficiency if you have a working system. Wood driven steam sucked, but it drove the industrial revolution because there was literally no other viable alternative at the time that could have remotely scaled in the same way.

Remember grid scale solutions require MASSIVE energy capabilities. The scale here is ridiculous compared to home or vehicle energy requirements. If you don't think Goldman Sachs took all of this into account before they made their investment - well, you are grossly mistaken. You don't get to be their size by continually placing bad bets.

robomartin2• 5 years ago

If I am going to put on my conspiracy theory hat on for a moment, here's the only reason I would think the investment is sound: Goldman Sachs knows our government will throw money at this despite it being a bad idea. Therefore, the company will make money on paper by effectively becoming yet another subsidized entity of sorts...all in the name of saving the planet (or some other popular delusional statement).

Nuclear is probably the only path to long term clean energy. I hope people eventually wake up to that reality. Sadly, we are going to burn lots of time, money and resources before we get to that moment.

tonke90• 5 years ago

There is already something like this in Germany, it even also talks about saving the heat: https://www2.ipp.mpg.de/ippcms/ep/ausgaben/ep200801/0108_spe... (German)

mwattsun• 5 years ago

From another link on the front page the Amish use the term "Amish Electricity" so this would be an Amish Battery

Amish Hackers

https://news.ycombinator.com/item?id=29905288

smm11• 5 years ago

I had a huge burrito last night, and I am as I type, a massive compressed air storage device.

nabla9• 5 years ago

Just cheeked some levelized utility scale costs for the US:

Advanced Nuclear is of $72/MWh.

Wind onshore $30/Mwh

Solar photovoltaic (PV) $30/Mwh

Lithium-ion battery storage is roughly $180/Mwh.

At the moment, if you want to provide baseload better than nuclear using renewables, the cost must of storage must not exceed $30-$40/Mwh.

(grid baseload is the minimum level of demand on an electrical grid over a span of time, something unvarying power plants are best suited for. Renewables require storage and advanced grid to provide baseload.)

treyfitty• 5 years ago

I remember reading this article a few years ago that Goldman Sachs. It's paywalled but the basics was that GS stores energy during the night, and uses the energy during the day. I thought it was neat, but they're obviously not new to this concept.

https://www.bloomberg.com/news/articles/2014-08-01/goldman-s...

Melatonic6• 5 years ago

I think this is a great idea if you have systems that also use compressed air to function. If you need to convert compressed air to electricity the inherent losses in that conversion seem like they just would not be worth it as battery tech increases.

Would love to see DC to DC grids become a thing again and it looks like they may - crazy to think that SF still has a fully operating DC grid powering all kinds of stuff.

seedragons• 5 years ago

Not a single "hot air" joke? Not sure to be impressed everyone's more mature than me or disappointed.

reacharavindh• 5 years ago

I’m not an electrical engineer. But, thinking about the power storage/retrieval problem with a computer engineer’s lens, I can draw a parallel to data storage/retrieval.

L1/L2/L3 caches - expensive, small, but fast.

RAM - mid tier, still fast, bigger than cache, less expensive than cache, but limited in capacity compared to disk/flash based storage.

SSDs…

Disks….

You get the point.

Would it be the same with the grid?

Several power sources - nuclear, solar, wind, hydro, hopefully not coal and gas.

Banks of Lithium batteries acting as first level(efficient and immediate but limited capacity storage).

Whatever excess is directed to longer term, non immediate storage - pump up water to generate power later, molten salt, air compression etc.

Even more left? - spin up production of time insensitive materials that would be used anyway later - sea water desalination plants, green hydrogen generation, sewage treatment etc.

At large scale such tiered ecosystems would be very cool and super useful.

loceng• 5 years ago

I've wondered if putting an compressed air energy storage system under certain types of buildings would work. Any thoughts on that? E.g. Apple's Ring HQ is already on a floating system to counter earthquakes, so why not add a layer of air? Unnecessary? Much more expensive than other options? Else?

beders• 5 years ago

Stanford researcher Mark Z. Jacobson makes a similar case but with renewables and storage only: https://web.stanford.edu/group/efmh/jacobson/WWSBook/WWSBook...

stcredzero• 5 years ago

Look into natural gas trading and scheduling. There's already an entire body of knowledge around storing energy, and sophisticated automated contracts, financial instruments, laws, and regulations. "Pools" are just energy storage, and the same geologic features used for those facilities could be used for compressed air storage.

(EDIT: I used to do this software!)

trompetenaccoun2• 5 years ago

Sounds trivial enough, now someone just has to built it all.

Jokes aside though everything has pros and cons. For storing large amounts of energy from the grid, are you sure lithium batteries make sense? Take a look at this, it's not a scientific article but it gives you a basic overview of the problems we'd face when storing energy in lithium batteries at scale: https://www.renewableenergyworld.com/storage/lithium-or-vana...

And that isn't to say that flow batteries are the ultimate solution either, we will have to do better because it's still very expensive.

epistasis8• 5 years ago

That article is from 2014. Since then we have deployed dozens of GWh of grid storage. There have been a few small fires, but otherwise it's worked out really well. Lithium ion on the grid is nearly doubling every year, and in places like Texas. I'm having trouble finding a recent article, but this one from 2020 has 3x as many battery GW thank gas GW in the interconnection queue:

https://pv-magazine-usa.com/2020/09/08/interconnection-queue...

And if you check out RV and boat forums, you'll find that small scale lithium ion batteries plus solar are enabling a huge change in power for these mobile applications, because it's just damn cheap these days.

hinkley• 5 years ago

Dave Borlace (Just Have a Think) has been covering this space a bit. There's a whole space in power storage that also overlaps with carbon capture that I suspect will probably end up being the winning play because cogeneration can often double system efficiency, making unprofitable things profitable.

One way we can reduce carbon intensity is to stop using fossil fuels to generate industrial CO2.

There's a kind of metal-air battery that actually absorbs CO2 while charging, and emits it while discharging. There is also air liquification as power storage, in which you can separate the oxygen, carbon dioxide and nitrogen into different containers.

Goldman Sachs invests $250M in compressed air energy storage

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