Gravity batteries try to beat chemical ones with winches, weights, mine shafts • Hacker News Board

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

#211

Post by jacobolus » Sat, Apr 24, 2021, 6:33 PM UTC

masklinn wrote: post #194

Scoundreller wrote: post #165

Earlier quoted context omitted.

I was thinking what if we used buildings built on jacks as our source of mass. Big one are largely built on pilings anyway, and even small ones on softer ground. Going to be a lot of flexing though. Nice thing is that some of the “inefficient” heat may be usable on-site: and you may get compressed air as an output that could be usable directly.

> I was thinking what if we used buildings built on jacks as our source of mass. Then you've got no height. Plus buildings are not dense so it's a pain in the ass, and when (not if) the jacks fail you're out a building.

It’s amusing to think of whole houses getting jacked 100 ft into the air on giant stilts during the middle of the day when solar panels are operating, then slowly dropping to release the stored energy in the evening/morning.

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

#212

Post by cogman10 » Sat, Apr 24, 2021, 6:36 PM UTC

f6v wrote: post #160

cogman10 wrote: post #136

Earlier quoted context omitted.

This seems like a "running before we can walk" statement. Until we can handle day to day problems, it seems weird to worry about edge cases. I imagine as we transition to renewables and storage we will still have fossil fuel peeker plants to handle these sorts of snaps. It won't be until our power storage is far more beefed up that we'll shut those down, and that will take years.

> This seems like a "running before we can walk" statement. Europe tries to be at a forefront of green energy. No sun/wind is a real issue there, not just an edge case.

Right, and my point is that they aren't going to decommission all backup power until they are at the point where sun/wind/storage can actually be relied on for more than just the good days.

We have a long trip to get there, so why worry about a once in 3/5 year event? We wouldn't go a year without fossil fuels and say "Ok, that was it! Demolish all the plants right now!"

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

#213

Post by cogman10 » Sat, Apr 24, 2021, 6:40 PM UTC

ms4720 wrote: post #147

cogman10 wrote: post #136

Earlier quoted context omitted.

This seems like a "running before we can walk" statement. Until we can handle day to day problems, it seems weird to worry about edge cases. I imagine as we transition to renewables and storage we will still have fossil fuel peeker plants to handle these sorts of snaps. It won't be until our power storage is far more beefed up that we'll shut those down, and that will take years.

A cold snap like that can happen every 3-5 years, think really cold February. If you don't have the capacity to handle it people will die and lots of things will break. It is not an edgcase

It is when we aren't running 1 year on pure renewables. Let's worry about events that happen every 3 to 5 years when we've got 1 year of renewable only figured out.

It will take years before this is potentially a problem and by that time we'll likely have gone through a few cold snaps.

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

#214

Post by bluGill » Sat, Apr 24, 2021, 6:41 PM UTC

f6v wrote: post #179

masklinn wrote: post #89

Earlier quoted context omitted.

> Here's an idea: what if -- instead of digging a deep hole into the ground -- we use the tower of a wind turbine as the vertical space in which the weight is raised/lowered? First, there's not really any room in there, wind towers are built for the job, we don't add twice the amount of steel and an elevator shaft for funsies. Second, even if there were some room it would be inconsequential, you need a lot of crap ve…

> That's the issue with gravity: it's really not that strong The weakest of all forces, isn’t it?

We should always hold out for some new discovery that is weaker.

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

#215

Post by dmoy » Sat, Apr 24, 2021, 6:42 PM UTC

f6v wrote: post #179

masklinn wrote: post #89

Earlier quoted context omitted.

> Here's an idea: what if -- instead of digging a deep hole into the ground -- we use the tower of a wind turbine as the vertical space in which the weight is raised/lowered? First, there's not really any room in there, wind towers are built for the job, we don't add twice the amount of steel and an elevator shaft for funsies. Second, even if there were some room it would be inconsequential, you need a lot of crap ve…

> That's the issue with gravity: it's really not that strong The weakest of all forces, isn’t it?

Yes, by many, many, many orders of magnitude.

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

#216

Post by mbreese » Sat, Apr 24, 2021, 6:54 PM UTC

f6v wrote: post #179

masklinn wrote: post #89

Earlier quoted context omitted.

> Here's an idea: what if -- instead of digging a deep hole into the ground -- we use the tower of a wind turbine as the vertical space in which the weight is raised/lowered? First, there's not really any room in there, wind towers are built for the job, we don't add twice the amount of steel and an elevator shaft for funsies. Second, even if there were some room it would be inconsequential, you need a lot of crap ve…

> That's the issue with gravity: it's really not that strong The weakest of all forces, isn’t it?

Does that matter though? If it is weak to extract energy with gravity, then it should also be weak to “charge” the system against gravity. The weakness may push these systems to less “instantaneous” loads, but I don’t see why it would necessarily be bad to use gravity storage (as opposed to another mechanical method like pressure).

I’d love for someone to explain more though.

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

#217

Post by frankus » Sat, Apr 24, 2021, 6:55 PM UTC

goldenkey wrote: post #2

And these systems are way larger, more dangerous (wind) and not as efficient as magnetic bearing flywheels. https://en.wikipedia.org/wiki/Flywheel_energy_storage

One of the downsides (or maybe double-edged swords) of kinetic energy storage is that it's relatively easy to accidentally get all of the energy out at once.

A stick of butter and an 2-tonne truck at 216 km/h both "contain" about 1 kilowatt-hour of energy.

The butter could maybe burn your house down but the truck could easily kill a couple of dozen unprotected humans in a fraction of a second.

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

#218

Post by tatref » Sat, Apr 24, 2021, 6:55 PM UTC

f6v wrote: post #179

masklinn wrote: post #89

Earlier quoted context omitted.

> Here's an idea: what if -- instead of digging a deep hole into the ground -- we use the tower of a wind turbine as the vertical space in which the weight is raised/lowered? First, there's not really any room in there, wind towers are built for the job, we don't add twice the amount of steel and an elevator shaft for funsies. Second, even if there were some room it would be inconsequential, you need a lot of crap ve…

> That's the issue with gravity: it's really not that strong The weakest of all forces, isn’t it?

It depends on the distance

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

#219

Post by hn_throwaway_99 » Sat, Apr 24, 2021, 7:01 PM UTC

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…

Agreed. I'm glad that people and companies are trying different solutions for our energy challenges, but I see so many examples where the basic physics make these solutions impossible to scale, that it seems like these are primarily just schemes to suck government money.

Gravity solutions like these will never be feasible, because as you point out, gravity is just plain too weak of a force. I mean, it looks like pumped hydro will be viable, but when you think of the sheer mass of water that can be pumped behind the Hoover damn you realize stacking a bunch of bricks is ridiculous in comparison.

There was another recent article on HN about a giant tidal generator, and I was glad to see the top comment pointing out that basically over 50 years all these tidal projects have been failures (at least when it comes to ever being able to provide decent power in a fashion that shows it can scale).

It's time we start calling out these schemes for what they are, because they take funding away from solutions that we now we'll need now to fight climate change.

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

#220

Post by Kenji » Sat, Apr 24, 2021, 7:07 PM UTC

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'm Swiss and I've been following this "technology" since its inception. Yes, it is a scam, I agree 100%. The maths never checks out, every engineer in this country knows this. We are all ashamed.