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Gravity batteries try to beat chemical ones with winches, weights, mine shafts

sciencemag.org

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Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#251

Post by throwaway189262 »

_liww wrote: post #233
throwaway189262 wrote: post #105

This is an obvious scam if you do the math. Assuming the full scale version delivers peak power for 11 seconds like the prototype, 2MW peak power would be 6 kilowatt hours of energy. That's terrible. We're taking about dropping hundreds, maybe thousands of tons down a mine shaft to get the same amount of power as $700 of lithium batteries you could carry in a backpack. For instantaneous loads you're way better off us…

Is anyone trying to implement that gas bag idea? Not one I'd heard of before

I heard conjecture about it. Possibly more realistic is high pressure gas storage in salt domes. Or hydro power based on filling and draining deep mines.

There's realistic gravity based projects, but dropping ACME style anvils down mineshafts isn't one :)

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#252

Post by throwaway189262 »

Youden wrote: post #226
throwaway189262 wrote: post #105

This is an obvious scam if you do the math. Assuming the full scale version delivers peak power for 11 seconds like the prototype, 2MW peak power would be 6 kilowatt hours of energy. That's terrible. We're taking about dropping hundreds, maybe thousands of tons down a mine shaft to get the same amount of power as $700 of lithium batteries you could carry in a backpack. For instantaneous loads you're way better off us…

> This is an obvious scam if you do the math. Reading the rest of your comment, I'm not sure you did the math yourself... > Assuming the full scale version delivers peak power for 11 seconds like the prototype The prototype is a 4-storey tower (i.e. less than 20m). > That's terrible. We're taking about dropping hundreds, maybe thousands of tons down a mine shaft A mine shaft can be expected to be significantly deeper…

Even 400 stories would be 600 kwh. Thats like 2 tesla battery packs. Way better than 6 but still not anything that can be realistically applied at scale.

There's not many deep mineshafts that aren't filled with water. And dewatering mines is insanely expensive. And 600 Kwh is nothing. Enough to power maybe 30 houses for a day.

My math is bad, but there's no math where this will ever work out profitably

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#253

Post by throwaway189262 »

rakoo wrote: post #237
yunohn wrote: post #149

Earlier quoted context omitted.

Please link to a source/calculation where a wind turbine uses more resources than a coal plant to build. I mean, you can even do napkin math and see that there’s no way multiple buildings and vast mining infrastructure take less material than a turbine farm.

If you want to take a coal plant, you have to compare it with something that's comparable. A coal plant is a 1000MW machinery. A wind turbine is in the order of 10MW. Also, turbines have a very low capacity factor so you have to double them to guarantee their output and combine them with storage. So it's 1 coal plant vs 200 turbines at the very least.

But coal plants use an absurd amount of coal and everything they don't burn ends up as ash.

And have you been close to a big coal plant? They're massive. A coal plant probably used more land than 200 turbines and unlike turbines the land is unusable.

Coal plants use many times their mass in coal during their lifetime. If you're looking at total materials needed over the lifetime of the plant, I wouldn't be surprised if coal was 100X higher than 200 turbines.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#254

Post by throwaway189262 »

michaelbuckbee wrote: post #153
lai-yin wrote: post #118

Earlier quoted context omitted.

Land AND resource use. Just because a single wind turbine takes up a small patch of land doesn't mean it's not extremely resource intensive. Case in point: https://twitter.com/extrachelle/status/986599367049179136?s=...

I was curious about total life cycle CO2 output and found an study in Nature. It looks like: - Hydropower + Bioenergy -> 100 gCO2eq kWh−1 - Traditional fossil fuels -> 78–110 gCO2eq kWh−1 - Nuclear, Wind and Solar -> 3.5–12 gCO2eq kWh−1 https://www.nature.com/articles/s41560-017-0032-9

This is actual supporting data from a reliable source and should be up top.

So it appears fossil fuels take ten times more energy to run over a lifetime. Less than I expected but still bad

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#255

Post by throwaway189262 »

waynecochran wrote: post #166
throwaway189262 wrote: post #100

Earlier quoted context omitted.

> as a single wind turbine, which is already one of the worst ratio of power output per quantity of resource and land use. This is just false. Every wind turbine I've ever seen uses 50 square feet on a farm or cattle ranch. Not once have I seen a wind farm where the land underneath isn't still used for it's previous purpose. And at least in US we have enough farmland to power entire US with wind. And that's not count…

The problem with wind is storing the energy. I live in the Pacific NW and when you drive through the Columbia Gorge you see hundreds of these windmills. I have have visited the Wild Horse Wind facilities and they store energy using batteries -- terrible. The dams below can back up water, but wind blows whenever is may. The dams also provide safety from flood, a waterway, recreation, ... windmills just pollute the sky…

Are you actually complaining that wind is bad because it ruins the view?

Windows, cars, and pet cats kill multitudes more birds than windmills

Hydro plants do use wind to bank energy. Either by shutting down and banking water when the wind is blowing, or even running the pumps in reverse.

I agree with you that energy storage is a big problem with wind. It is with solar too. But we can get near 50% wind and solar before it becomes a problem since much more energy is used during the day.

Dams also have a finite lifetime, something nobody really talks about. They silt up over 50-100 years until they're completely full. This is a bigger problem in places like China with turbid water but happens everywhere eventually. The sun will shine and wind will blown till long after we're gone but dam sites will be gone eventually.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#256

Post by jasonwatkinspdx »

waynecochran wrote: post #246
jasonwatkinspdx wrote: post #242

Earlier quoted context omitted.

You misunderstand the impact of the dams on the ecosystem. Salmon are hanging by a thread in the Columbia, and only a very aggressive hatchery program has kept them from collapse. Essentially all buildable sites have already been built, and there's a growing awareness some existing damns need to come down. The Gorge is not some great untapped resource for pumped storage that people were too distracted by wind power t…

Salmon are good -- I fish there. Salmon are even spawning well above the dams. I don't know where folks get that misinformation.

I'm friends with an environmental economist that did the analysis while working for the state of Oregon. He also was involved in the reports that shut down Boardman. The information is accurate.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#257

Post by xelxebar »

Dylan16807 wrote: post #231
Youden wrote: post #226

Earlier quoted context omitted.

> This is an obvious scam if you do the math. Reading the rest of your comment, I'm not sure you did the math yourself... > Assuming the full scale version delivers peak power for 11 seconds like the prototype The prototype is a 4-storey tower (i.e. less than 20m). > That's terrible. We're taking about dropping hundreds, maybe thousands of tons down a mine shaft A mine shaft can be expected to be significantly deeper…

> From TFA itself, they estimate they can offer a price of $171/MWh, while Lithium-ion batteries cost $367/MWh. With absolutely nothing to explain the cost estimate, so you can put away "TFA" thank you. A system like this with only a single weight is going to be a huge amount of work to set up each unit of capacity. Also looking up the info I can find, I think they're calculating that rate over a 60 year lifetime. Ed…

> Uh, did I say something offensive?

No that I see. It's just really easy to read your comments in a haughty tone, which naturally selects for downvotes. The content of your posts, on the other hand, seems to encourage deeper investigation, so that's probably on point.

Communication is hard.

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#258

Post by jodrellblank »

BenjiWiebe wrote: post #230
jodrellblank wrote: post #177

Earlier quoted context omitted.

> " a 5m tall tower bearing 73 tonnes to store 1 kilowatt hour " By comparison, a pint of gasoline stores about 4 kilowatt hours.

Too bad we can't just synthesize gasoline with electricity at a decent efficiency.

There is a tree which produces a biodiesel substance at a rate of 40 litres/tree/year.

https://www.smh.com.au/national/farmer-planning-diesel-tree-...

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#259

Post by sesuximo »

015a wrote: post #225
throwaway189262 wrote: post #105

This is an obvious scam if you do the math. Assuming the full scale version delivers peak power for 11 seconds like the prototype, 2MW peak power would be 6 kilowatt hours of energy. That's terrible. We're taking about dropping hundreds, maybe thousands of tons down a mine shaft to get the same amount of power as $700 of lithium batteries you could carry in a backpack. For instantaneous loads you're way better off us…

I think an important thing to note about gravity batteries is how environmentally friendly they are, even relative to lithium ion batteries. Lithium mining is an insanely tight bottleneck in LI battery production, mostly outsourced to countries where we don't think much about it (Australia is a big one right now, but in terms of untapped reserves, Chile Argentina and China are all huge). They require complicated manu…

Yeah, but mine shafts are not exactly abundant either

Re: Gravity batteries try to beat chemical ones with winches, weights, mine shafts

#260

Post by thehappypm »

masklinn wrote: post #123
thehappypm wrote: post #108

Earlier quoted context omitted.

I’ve always been surprised that there is no product wind turbine with a guaranteed power output, that is, a turbine with an embedded battery. Sure it would cost much more, but in some applications steady power is worth it.

> Sure it would cost much more, but in some applications steady power is worth it. It would cost much more and be way more complicated & less reliable than… just getting the two separately and using battery grid storage on the output of the windfarm. Even for a backyard turbine it wouldn't make much sense, for maintenance reasons you'd want to manage your turbine and storage separately, and if, say, you add solar pan…

Why would it be more complicated and less reliable than getting them separately? I understand that it would be a more complex product for GE but for a turbine buyer it sounds extremely attractive
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