Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

sciencemag.org

Post reply on HN
Print view View original

161–170 of 278 posts

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

#161

Post by jdmichal »

dopidopHN wrote: post #138
hutzlibu wrote: post #79

Earlier quoted context omitted.

"Also, we already have gravity-based systems, only nature does all the work of raising the payload for us in gaseous form, and we let it fall in liquid forms. But it takes so much dam place" We actually also do have self created gravity-based systems, where we also do the work by ourself, to have a energy storage on demand: https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... They work reliable and with bi…

Side note on what is currently existing with gravity. The suiss folks are gaming the west European energy market this way. When the French produce too much nuclear energy, the German have leftover and stop buying it 100%w Price go down. Swiss buy it cheap and pump water in their dam system with it. Inevitably, the french grid align and produce a bit less. Price goes up slightly. That when the suiss comes out, release…

> Price goes up slightly.

How much of a swing in pricing are we talking about here? Because that storage mechanism is maybe 80% efficient. So the price swing would have to be at least that big to break even. And in that case, if they are helping to smooth out swings in demand that are that large... Sounds like they're providing a valuable service.

https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...

EDIT: Keep in mind that electricity is entirely fungible. This is no different than the Swiss turning on a power plant when prices are higher. Except it would probably be too expensive to have a power plant just sitting there idle when the price isn't "high enough".

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

#162

Post by marcosdumay »

berkes wrote: post #91
FooHentai wrote: post #73

Earlier quoted context omitted.

I did a bit of scratch math with the notion this might be more suited for individual, home power storage rather than grid supply - You need something in the order of a 5m tall tower bearing 73 tonnes to store 1 kilowatt hour (even then, ignoring conversion losses). So that's the weight of ~ten class-4 fully laden heavy trucks. Once you can get it up in the air then the higher you can go you're doubling your storage i…

I can imagine this tech all packed up in a standard 40ft shipping container and dropped on premise. This would be rather simple tech, that can supplement solar and wind on your farm, lodge, campsite or island. Another piece in the puzzle for smaller scale independence. Not to replace metropolis-scale energy demands, as grandparent implies, but to smooth out fluctuations on hourly, household scale.

I imagine chemical batteries would be easier to ship and install, and require less maintenance. I really can't imagine any mechanical system that involves plugging and unplugging a load (or anything more complex than that) to be useful at small scales.

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

#163

Post by SarbinBracklur »

The numbers in this article seem off. 250kW (peak power) for 11s (time at peak power) is 2.75 MJ. That's only about 51 10000mAh D batteries. Of course, the peak power of the gravity battery is much higher than the chemical batteries, but still.

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

#164

Post by bjourne »

martinald wrote: post #127
audunw wrote: post #90

Earlier quoted context omitted.

It's a common misconception that energy storage needs to handle all the power needs of an area for a significant time. The most immediate need for energy storage is frequency regulation, and short hours-long dips in power output. If we can solve that we can scale renewables very far. For days-long dips in power output, it's probably better to keep some gas power plants on stand-by. I think many areas of the world has…

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…

Homes in the UK are poorly insulated, likely due to a previous over-reliance on fossil fuels. https://www.theguardian.com/environment/damian-carrington-bl... Better insulation and switching to district heating where applicable could yield massive savings.

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

#165

Post by Scoundreller »

thirdlamp wrote: post #94
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…

What if we used load bearing batteries as part of the tower structure?

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.

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

#166

Post by waynecochran »

throwaway189262 wrote: post #100
rakoo wrote: post #48

As usual everyone is fixated on price when the real hurdle will be scale. If we're going to replace our existing fossil fuel plants we need at least as much capacity. A quick grep in the article tells me these guys have a plan for a 4MW plant that involves a 1km shaft. That's the same order of magnitude as a single wind turbine, which is already one of the worst ratio of power output per quantity of resource and land…

> 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, kill song birds, and can not produce energy on demand nor store it effectively. Talk to engineers for Bonneville and they mock the windmills.

If they are going to use wind why not pump water up from the Columbia River up to the top of the surrounding hills? Use the potential energy at least.

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

#167

Post by iandanforth »

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 battery thing a stack of dirt shelves that go up and down and while they are going up and down they also grow plants in the dirt.

So now you have a big field of these dirt stacks going up and down and in the middle you have a big farmers market. Money from dirt two ways. God how is this not already a thing.

Problems solved. Done.

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

#168

Post by bjourne »

hutzlibu wrote: post #145
dopidopHN wrote: post #138

Earlier quoted context omitted.

Side note on what is currently existing with gravity. The suiss folks are gaming the west European energy market this way. When the French produce too much nuclear energy, the German have leftover and stop buying it 100%w Price go down. Swiss buy it cheap and pump water in their dam system with it. Inevitably, the french grid align and produce a bit less. Price goes up slightly. That when the suiss comes out, release…

Maybe I do not understand it fully (ne pas parle de francais), but where do they game the system? You buy cheap when you have storage and sell expensive when demand goes up. Pretty much how the market should work? This way there is incentive to balance it out (by creating storage) - and in this case stabilize the grid. When the grid would become more flexible, so even homeowners can do this with their solar panels an…

It's not gaming the system, it is arbitrage. However, it is pretty terrible for producers unable to exploit price swings. E.g a nuclear plant produces electricity at a fixed cost and may sell it at a loss when the price is low, but recoups the losses when the price is high. Since arbitrage smooth out the price peaks, it damages nuclear's profitability. One could say that's too bad for nuclear, others (nuclear lobbyists) say that regulation is needed to prevent electricity arbitrage.

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

#169

Post by eloff »

martinald wrote: post #127
audunw wrote: post #90

Earlier quoted context omitted.

It's a common misconception that energy storage needs to handle all the power needs of an area for a significant time. The most immediate need for energy storage is frequency regulation, and short hours-long dips in power output. If we can solve that we can scale renewables very far. For days-long dips in power output, it's probably better to keep some gas power plants on stand-by. I think many areas of the world has…

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…

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.

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

#170

Post by kortex »

kstenerud wrote: post #146
audunw wrote: post #90

Earlier quoted context omitted.

It's a common misconception that energy storage needs to handle all the power needs of an area for a significant time. The most immediate need for energy storage is frequency regulation, and short hours-long dips in power output. If we can solve that we can scale renewables very far. For days-long dips in power output, it's probably better to keep some gas power plants on stand-by. I think many areas of the world has…

Actually, almost none of our trash is recyclable (despite what you've heard). Plastic is particularly bad, and it's only now, with China banning import of "recyclable" materials, that we're finally seeing just how much of a farce it is. Burying it is a form of CO2 sequestration. Burning it just releases it into the atmosphere.

But it's already out of the ground. I'd rather burn 1T CO2 worth of plastic trash made from oil and prevent 1T CO2 worth of coal or heavy oil being extracted and burnt. Not that it's 1-to-1, point is burying plastic is probably less net carbon vs burning.
Post reply on HN