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

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

#151

Post by patall »

patall wrote: post #142
runeks wrote: post #76

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? A wind turbine is already equipped with a generator, so it'd be a matter of building some sort of "switch" which would make it either: (a) generate electricity using the turbine, as per usual; (b) raise the weight using the turbine, thus not produ…

Funny how people tell you that that this does not make any sense at all, but here it is: http://www.naturspeicher.de/en/naturstromspeicher.php (Yes, I am aware that it is not storing the water at the top :)

Furthermore, there exists the opposite concept of replacing water with air deep in the sea: https://www.iee.fraunhofer.de/en/research_projects/search/20...

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

#152

Post by martinald »

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's actually worse than that, there are many days in winter in the UK with high demand and virtually no solar/wind output. But obviously a really cold snap would be even worse (and as you said isn't an edge case - even if it is look at the damage that happened in Texas when it wasn't accounted for)

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

#153

Post by michaelbuckbee »

lai-yin wrote: post #118
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…

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

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

#154

Post by martinald »

ianai wrote: post #141
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…

I’d just build the generation out to that maximal use case. During the off peak times power a desalination, hydrogen, or other energy intensive plant.

The problem is the UK sees maybe 1-2GW of renewable generation sometimes in winter while demand is about 50GW. So you'd have to overbuild 25x to cope with these days.

Keep in mind the UK already has about 30GW of solar and wind potential nameplate capacity. Your suggestion would result in a requirement of 700GW of solar and wind to be installed. On windy and sunny days would result in probably 350GW of generation, at least 300GW more than we need.

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

#155

Post by Retric »

ben_w wrote: post #135
pedrocr wrote: post #68

Earlier quoted context omitted.

That's the wrong comparison. We don't need to replace generation capacity with the same capacity of batteries. Batteries don't generate any electricity after all. We need batteries to smooth out differences between demand and generation. The total amount we'll need is very much still up in the air. Better interconnects, good use of existing hydro, overbuilding renewables, shaping demand, are all other ways to balance…

I think[0] we should probably be aiming for a few hours of storage, even with every affordable grid interconnect (which would help a lot with short winter days). We use less power at night — and some of what we do use is incentivised by lower nighttime electricity costs from power plants that don’t scale down well — but I expect we will continue to use some at night forever. For the sake of Fermi estimation, I assume…

Large scale hydro electric dams are already large scale batteries across months. The specific day of the week energy is released is not particularly relevant let alone time of day. 6.6% of US electricity is from hydro, assuming 2/3 flexable your looking at 4.4% of daily power demand or ~1 hour of full grid storage every day is already built.

Excess capacity is required for storage to work and reduces the need for energy storage. But, once you start talking excess capacity, transmission dramatically reduces the need for storage.

Assuming storage costs say 2x as much as wind generation then building excess wind capacity is worth it until ~1/2 of a wind turbines output is wasted. Thus if we are looking at 3kWh of storage that can be banked at any time of the day we are looking at a lot of excess capacity, yet somehow still supposed to have a 3kWh per night deficit.

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

#156

Post by kjrose »

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…

You are absolutely dead on right. We need to stop trying to bang on a model that isn't working and be willing to think even more outside of the box.

All of this is essentially ways to create hydroelectric plants without the water. If we can find a way to create more of them without massive disruption it'd probably be the most effective.

We need to find a solution that isn't just based on good wishes.

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

#157

Post by throwaway189262 »

wizzwizz4 wrote: post #133
throwaway189262 wrote: post #131

Earlier quoted context omitted.

It does far less damage than any other source of power. Unlike solar, it uses no space. Unlike fossil fuel and nuclear, it uses no continuous inputs. Coal and gas plants use many times their weight in materials for a lifetime of operation. Nuclear probably does too because the massive waste involve in uranium refining. What do you suggest as a greener power source than wind?

> Unlike wind, it uses no space. Unlike solar?

Lol yeah

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

#159

Post by marcosdumay »

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…

You mean they are selling large scale storage and managed to turn a profit?

That sounds great. They are first, but as we deploy more renewables, we'll need much more cases like this.

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

#160

Post by f6v »

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.

> 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.

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