Live data from Hacker News

Goldman Sachs invests $250M in compressed air energy storage

canarymedia.com

151–160 of 325 posts

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

#151
post #119

Earlier quoted context omitted.

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

Like a giant rotating wind turbine?

i agree, wind turbines do rotate but not at high speeds, disintegration of one doesn’t lead to catastrophic outcomes. Flywheels on the other hand are meant to rotate at high speeds and hold lots of energy, so destruction of the spindle would lead to some pretty big bad results

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

#152

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.

[deleted]

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

#154

Earlier quoted context omitted.

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…

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?

Buy low and sell high. They can find surplus power and buy it cheap, then wait until there are unmet demands and sell high.

These crazy things called computers make creating and automating markets like that pretty easy :)

It's win win - the people with surplus power can at least get some money for energy that would otherwise likely go to waste (large base load power plants can't ramp up and down on a dime) and on the flip side if you have an energy provider that only occasionally needs capacity in excess of their inherent generation even though the immediate cost is higher for spot power, it can still be far cheaper in the long term than building more base load generation (often fossil fuel because renewable still isn't a viable replacement for base loads). And running base load generation under capacity is wasteful for emissions and overall efficiency.

Once we start to crack the whole energy storage thing renewables will be A LOT more valuable since we will be able to start to use them for base load. Storage allows you to create reliable energy delivery that's predictable - that's essential if we ever want to eject fossil fuels from the grid. Or we could stop being childish about nuclear power - frankly I think we can solve the storage problem long before we can convince people to be rational about nuclear :p

It probably seems crazy for the uninitiated, but there are a lot of efficiencies in markets that occur naturally over time. You see distortions in the market from CA's stupid and politically motivated choices - what seems crazy to you is the market adapting to the model that CA is forcing. Is it nuts? Yup. Is it necessary? Nope - these wounds are entirely self inflicted. Pretending the world is different than it actually is doesn't solve anything and the people of CA are paying a hell of a lot more for electricity because they are trying to live in a pipe dream for where we are today.

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

#156
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…

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…

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.

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

#157

Earlier quoted context omitted.

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…

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?

There are times where the rooftop solar and base load generation for a utility is greater than the total electricity demand. Demand and supply for the grid have to be balanced, or else you will end up tripping plants and/or damaging equipment. Since they can't "turn off" rooftop and most grid scale solar generation, and they can't really turn off and on their base load plants throughout the day, their best option is to try to sell the excess electricity on the wholesale market. The problem is that the other utilities are in the same situation, and they need to offload electricity. Since no one wants the electricity, wholesale prices will actually go negative. Basically a utility will pay another utility to turn off a base load plant and take the excess electricity from them.

This is why grid scale energy storage is such a hyped technology - if you can store that energy when supply is way too high and dispatch it when renewable generation is low (no wind/solar), you can maintain high renewable percentage in the generation mix. Without it, you can only really go up to a certain percentage of renewables.

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

#158
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.

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

#159
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...

Post reply on HN