This is based on an annotation posted under "Wind Turbine Gravity Storage".
To begin, one needs a huge, heavy, disc-shaped, lead-acid battery pack --- perhaps 10 feet in diameter and 5 feet high.
When one has excess energy to store --- such as that from wind and solar --- one first uses it to charge the batteries. If there's any more after they're charged, it's used to lift the battery pack up along a tall pole (potential energy). And finally, if there's any more after it's lifted to the top of the pole, it is used to spin the battery pack (rotational energy). So, that's three forms of energy storage in one, all of them sharing some of the physical components.
One could go further, and use a solid state heat pump to transfer heat from half of the battery pack to the other to create a temperature differential. This energy would be recovered using the heat pump in thermo-electric mode.
This has little to no serious potential, as no one is going to want huge amounts of lead and acid spinning far above the heads. It would be a disaster waiting to happen. Added Oct 7, 2016: For an additional storage method, (to be used before the thermal method), one could have the batteries mounted on leaf-springs, then energy could be stored by causing them to vibrate back and forth toward and away from the center of the battery pack. They would need to be vibrated in pairs, of course. Each pair would be synchronized: going toward and away from the center at the same time. To eliminate changes in the concentration of mass, and the resulting changes in rotational speed, the pairs beside any given pair would be 180° out of phase with it.-- Alvin, Sep 11 2016 Electric Mountain http://www.electricmountain.co.uk/Dinorwig Power Station - a pretty impressive energy storage facility. They pump water up to the top of the mountain and store it in a big lake which can be released very quickly through hydroelectric generators, allowing it to go from 0 MW to 1800 MW in about 16 seconds [hippo, Sep 12 2016] https://www.damnint...mechanical-battery/ [2 fries shy of a happy meal, Sep 12 2016] Didn't something similar appear here recently?-- MaxwellBuchanan, Sep 11 2016 Many lead-acid batteries these days are sealed; they won't leak. Of course if they fall from a height and break upon impact, that's different. Perhaps the potential crash zone should be layered with cushioning.-- Vernon, Sep 11 2016 [bigsleep], what part of "potential crash zone" doesn't include "dispersal radius"?-- Vernon, Sep 12 2016 Interplay of different things and actions is away of making unique cases happen. The more unique cases we can find, dimension and technofy, the more humans can progress.
It is never known when we will uncover the next beneficial anomally, so any weird and wonderful experiment is valid.-- wjt, Sep 12 2016 If you spin the battery fast enough, you'll be broadcasting radio.-- MaxwellBuchanan, Sep 12 2016 @bigsleep My expectation, based on studies long ago, is that each conversion of energy between chemical, electrical and mechanical form could range from 80% to 95%. Recovery of thermal energy is not expected to be worth the bother. I was just seeing how far the combining of energy storage methods could be taken.-- Alvin, Sep 12 2016 I guess the question is whether the lifting and spinning can store more energy than could be stored by batteries occupying the same space as the equipment needed to lift and spin.-- MaxwellBuchanan, Sep 12 2016 Yes. Much more energy can be stored mechanically just with spin alone. From the [link]:
A traditional lead-acid cell— the battery most often used in heavy-duty power applications— stores energy at a density of 30-40 watt-hours per kilogram: enough to power a 100-watt bulb for about 20 minutes. A flywheel-based battery, on the other hand, can reach energy densities 3-4 times higher, at around 100-130 watt-hours per kilogram. Unlike the battery, the flywheel can also store and discharge all that energy rapidly without being damaged, meaning it can charge up to full capacity within minutes instead of hours and deliver up to one hundred times more power than a conventional battery. What’s more, it’s unaffected by extreme temperatures, boasts an efficiency of 85-95%, and has a lifespan measured in decades rather than years.
I love this idea. (+)-- 2 fries shy of a happy meal, Sep 12 2016 [MaxwellBuchanan], there is also the matter of energy- conversion efficiency. Mechanical conversions from lift and spin, to electricity, can be 95% efficient Batteries are much less efficient, converting chemical to electrical energy. Now if the whole thing was built of supercapacitors (nearly 100% efficient)....-- Vernon, Sep 12 2016 I'm not about to make a flywheel out of lead. That seems like a horrendously bad idea.-- RayfordSteele, Sep 12 2016 //there is also the matter of energy- conversion efficiency//
Yes, that's true. My main point, though, was that just lifting or spinning a battery (assuming that the battery is the primary storage device) isn't necessarily cost-free, since the lifting and spinning equipment takes up space, cost and mass which might be better used on having more batteries.-- MaxwellBuchanan, Sep 12 2016 Yeah I'm thinking this is going to suffer the design problem of the x that also does y and z, and none of them well. See also the F35 JSF.-- RayfordSteele, Sep 12 2016 Added vibration-energy storage method to article.-- Alvin, Oct 08 2016 Given the whole E=Mc^2 business, it's clear that even a large amount of energy has very little mass. Therefore, we should be able to trap it, like helium, under a huge imperveable tent-like structure, staked to the ground.-- MaxwellBuchanan, Oct 08 2016 //I'm not about to make a flywheel out of lead. That seems like a horrendously bad idea.
Ok, try depleted uranium...or for more fun, non-depleted...-- not_morrison_rm, Oct 08 2016 Actually, //Given the whole E=Mc^2 business//, why don't we just use energy to create mass (antimatter sounds like a promising material), and store that for later back-conversion to energy?-- MaxwellBuchanan, Oct 08 2016 We don't know. It's so simple... probably just that your species is too stupid to have worked out how to do it yet.
// for more fun, non-depleted //
We can state definitively that NUM is just as fun as DU; which, unless impacting a metal surface at 600m/s or more, is basically pretty damned dull.
Being pyrophoric, the turnings spontaneously ignite when it's machined, but that's about it. You can have more fun with a roll of magnesium ribbon, and the fumes are slightly less likely to cause bone cancer and/or leukemia.
Enriched Uranium is, however, highly entertaining in the right circumstances (stand well back, preferably behind something substantial, like the Andes).-- 8th of 7, Oct 08 2016 random, halfbakery