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.Reply
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.
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.Reply
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!Reply
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.Reply
What is the expected efficiency of this?Reply
Interesting, I guess the water freeze isn’t a problem in those placesReply
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?Reply
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.Reply
Does this technology only work in select places or are underground caverns fairly commonplace?Reply
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.)Reply
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.Reply
There is a great post on compressed air energy storage (CAES) over at Low-Tech Magazine:Reply
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)Reply
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.Reply
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.Reply
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.Reply
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 . There's a beautiful discontinuity between one of the more tech-savvy old-guard banks and the technology-careful Amish adopting the same technology.Reply
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???Reply
That sounds dangerous.Reply
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.Reply
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.
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.Reply
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.Reply
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.Reply
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?Reply
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  says they get ~60% efficiency.Reply
I had a huge burrito last night, and I am as I type, a massive compressed air storage device.Reply
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.Reply
Not a single "hot air" joke? Not sure to be impressed everyone's more mature than me or disappointed.Reply
Given it's GS, $250m is peanuts.Reply
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.Reply
Has anybody considered building flywheels into each wind turbine?Reply
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?Reply
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 ). 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:  https://www.investorvillage.com/smbd.asp?mb=5028&mn=126049&p...Reply
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.Reply
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.Reply
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.Reply
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.Reply