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

#181

Post by f6v » Sat, Apr 24, 2021, 3:42 PM UTC

cheschire wrote: post #34

choeger wrote: post #13

Stopped reading at a total cost of more than $300 per MWh for batteries. Quick back-of-the-napkin calculation: Car batteries come in at less than $100/KWh. They're good for at least 1000 cycles at 80% capacity. That gives us at least 0.8MWh for a 100$ investment. It's very, very unlikely that initial construction of the site and operational costs more than triple that price.

I wish that cost basis wasn't the only consideration when evaluating energy storage, but we're so accustomed to money being the great equalizer that things without a financial cost associated are often overlooked. What is the $/MWh cost associated with mining for, recycling, and disposing of battery components? What about the third order effects of centralizing control over the fuel source within only a handful of co…

> What is the $/MWh cost associated with mining for, recycling, and disposing of battery components?

A chemical battery is rather compact, imagine how much stuff you need to build a gravitational mega-structure.

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

#182

Post by f6v » Sat, Apr 24, 2021, 3:45 PM UTC

iandanforth wrote: post #167

Ok, ok, everyone, I've got it. It's great. As you know, two meh ideas together make one galaxy-brain idea so here it is. Gravity batteries + vertical farming. This is so amazing I'm just jittering over here. So what are big shafts filled with before they are shafts? Dirt ! What do plants need to grow? Dirt ! So what you do is ... wow this is great ... what you do is you take the dirt out, then you make this big batte…

Peak HN, right here.

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

#183

Post by f6v » Sat, Apr 24, 2021, 3:48 PM UTC

imtringued wrote: post #114

flal_ wrote: post #55

Earlier quoted context omitted.

Yet, gravity is strong enough to initiate nuclear fusion at the core of stars, or create black holes... That 10^36 argument is non sensical to me.

Are you suggesting we should build a bigger planet?

We should have been smaller people with fewer needs.

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

#184

Post by goldenkey » Sat, Apr 24, 2021, 3:55 PM UTC

travisjungroth wrote: post #8

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

Now I want one. Home powered by solar and a flywheel is so retro-future. How does your house get electricity? Oh, power from the sun gets this flywheel spinning super fast and then it slows down and powers the house all night.

The heavier the flywheel, the less rpm you'll need for your storage requirements. Not sure how efficiency factors in. But yeah, would be awesome!

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

#185

Post by f6v » Sat, Apr 24, 2021, 3:57 PM UTC

nl wrote: post #30

jb775 wrote: post #18

It's crazy how little we understand about gravity if you think about it. It's a perpetual energy source right in front of us, but we never really think about it, and can barely offer a basic explanation as to what powers it. It even impacts time itself[1] for christ sake. I think better understanding gravity is the solution to all human energy needs. (interesting to note I have heard stories of disappeared scientists…

> It's crazy how little we understand about gravity if you think about it. We understand most things about it > It's a perpetual energy source right in front of us, No it's not. It's a good way to store energy but in no way is a source. > and can barely offer a basic explanation as to what powers it It's not something that has power. It's a consequence of entropy. > It even impacts time itself You sound surprised by…

> We understand most things about it

In a classical mechanics sense - yes. But the waves were detected just couple years ago.

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

#186

Post by danans » Sat, Apr 24, 2021, 4:01 PM UTC

stavros_ wrote: post #81

cheschire wrote: post #34

Earlier quoted context omitted.

I wish that cost basis wasn't the only consideration when evaluating energy storage, but we're so accustomed to money being the great equalizer that things without a financial cost associated are often overlooked. What is the $/MWh cost associated with mining for, recycling, and disposing of battery components? What about the third order effects of centralizing control over the fuel source within only a handful of co…

I agree. There's so much bullshit in mainstream energy analysis; there's too much incentive. Energy is central to civilization - what we use, where and how we get it, how we use it, how much of it there is and when we can use it - change any of those variables, change the shape of the entire civilization. Yet the conversation around energy technologies is entirely dominated by dollar cost. This obfuscates so much, an…

> That energy we'll one day need to feed ourselves, and heat our homes, and supply our medicines and materials? We're using it, right now, to make a shitload of disposable, toxic, plastic shit.

We should limit it's use to making medicines and materials instead of burning it to heat our homes and propel our cars.

Not only does the latter consume a lot more fossil fuels, it does so by dumping a lot more CO2 into the atmosphere. Plastics consume 14% of global petroleum production today [1].

We could ban all the "disposable, toxic plastic shit" tomorrow (and I agree that we should find ways to create a less disposable culture) and we would still have a huge CO2 problem caused by fossil fuel powered space heating, transportation and electricity production.

1. https://e360.yale.edu/features/the-plastics-pipeline-a-surge...

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

#187

Post by RosanaAnaDana » Sat, Apr 24, 2021, 4:14 PM UTC

What about pumping water up hill into reservoirs?

I know not every where is suitable for reservoirs but this seems pretty obvious. Run renewable to pump the water up hills, all the 'battery' components of the tech are well established. You're creating additional benefit by storing potentially potable water. It seems like the tech for water storage/ transport/ regeneration to electricity is all pretty well figured out. I'm thinking some place like the Columbia gorge where there is high capacity for wind and for hydro.

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

#188

Post by RosanaAnaDana » Sat, Apr 24, 2021, 4:22 PM UTC

bluescrn wrote: post #67

PurpleFoxy wrote: post #60

Earlier quoted context omitted.

Isn’t pumped hydro a realistic solution? There should be a massive amount of energy in moving all that water up a mountain.

Pumped storage hydro makes far more sense. Which is why it's already in use. Maybe the efficiency can be improved upon with a small-scale 'gravity battery', but water has massive advantages when it comes to scaling it up, as well as being able to combine it with traditional hydro, where nature moves much of the water for you.

Plenty of issues with hydro, but in the grand scheme of things, it does seem like by far the most accessible, actionable, least polluting option.

I've often wondered what scale of a system would be required to power a fully off the grid home at say 30kwh/ day, for say, 6 days? I'm imagining a tank based system with two tanks where the fluid is effectively just exchanged (so one doesn't have to account for the environmental impacts of a dam or for losses due to evaporation)..

After some googling: https://www.edie.net/library/Using-pumps-as-turbines-to-gene...

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

#189

Post by eloff » Sat, Apr 24, 2021, 4:29 PM UTC

after_care wrote: post #174

eloff wrote: post #169

Earlier quoted context omitted.

All the while the north sea with it's wind is right there, and the Sahara with it's sun nearby too. Some investment in long distance power transmission would go a long way towards smoothing out the grid.

Long distance power transmission is a significant political and military liability, not to mention a fantastic terrorist target. We cannot guarantee that the UK will be at peace with every county between them and the Sahara forever. Hosting the power line would grant significant political or military leverage.

You don't want a single point of failure. Having multiple lines across a geographic space is the way to go.

It's a big upfront investment, but it could be much cheaper than storage at scale.

I think ultimately you want power transmission stretching from the UK to Japan so as the sun moves the power generation continues.

I imagine it will happen one day, because it would seem to make so much sense, but this is something governments could make happen a lot sooner if they put their mind to it.

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

#190

Post by canadianfella » Sat, Apr 24, 2021, 4:35 PM UTC

cogman10 wrote: post #136

martinald wrote: post #127

Earlier quoted context omitted.

Not true in northern European countries. The problem isn't day to day regulation, it's the massive demand in cold snaps in winter (when there is very little wind generation - cold weather tends to have little wind). You're talking balancing 20-30GW of additional demand with little solar/wind generation for weeks/months - probably at least 1TWh of storage required for the UK alone. Keep in mind this will only get wors…

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.

People freezing to death isn’t an edge case.