This has certainly been baked separately, but the synergy's the thing here.
A major issue raised by nuke proponents and others concerning wind power is the uncertainty of the wind. A way to economically store energy for times when the wind is not blowing is therefore needed.
Wind turbine towers could have a cable attached to a large weight internal to the tower. At times of lower demand, the turning force of the blades could be disconnected from the generator and used to raise the weight to the top of the tower (hub heights are now up to 130 meters).
When power demand is high and the wind is not blowing, the blades would be disconnected from the generator, and the weight would be released to turn the generator via gravity and generate power.
While probably not a huge amount of storage, it would certainly increase the total output of the turbine, thus increasing their utility and smoothing out the production curve.
If you left the weight attached to the blades when descending, you could also create a nice breeze on a hot day. ;-)-- DrFever, Jul 18 2006 Heindl Energy http://www.heindl-energy.com/Larger-scale gravitational storage of energy using the weight of rock. I have an idea to improve it that I should get around to posting. [notexactly, Aug 29 2016] I quite like the idea, but I suggest that you dispense with the "nice breeze on a hot day" bit - since no person would notice it, but the energy put into turning the blades would be taken from what would potentially power the generator.
Any idea just how much power could be generated? I wouldn't expect loads - especially since dropping the weight is a one-time thing.-- fridge duck, Jul 18 2006 ...although similarly, dropping the water from the top to the bottom lake at Dinorwic in Wales is a one-time thing too. That generates a good few megawatts for several hours (note lack of facts) and helps stabilise the UK power grid.-- david_scothern, Jul 18 2006 Weren't windmills used to pump water up to a tank? Isn't that gravity storage?-- ldischler, Jul 18 2006 Lifting 1 metric tonne up a 130-meter tower results in 130,000 Kgf*m, or .354 KWh of stored energy.
my 100 watt light bulb burns .1 KWh/h
Assuming I do nothing more than light my house, and that energy recovery and transmission is 100%, the bulb would stay lit for a little more than 3.5 hours.
Granted, you could probably lift much more than one tonne, but I get the feeling that this energy could be put to better use by using the energy as fast as it is produced, and running other, more polluting power plants at a lower level.-- Freefall, Jul 18 2006 OK, fridge duck, smilie added...
Freefall - the problem I am trying to solve is that if you have enough polluting generation capacity to handle your peak loads, then you will not get major investment in wind power as it can not be counted on to help during those peaks. I am trying to get wind counted as part of the 'baseline' capacity.
Thanks for the numbers [Freefall], so if I can assume it wouldn't be too much trouble to lift 100 T, then that would be about 35 KWh, possibly stored and released up to twice per day. That would yield 70 KWh, at Ontario Hydro's rate of $0.17/KWh (for wind power into the grid) gives $11.90 (CDN) per day per turbine.
Thats $4345 per year in additional revenue for your investment. Not a lot, to be sure, but not negligible either I would say. Faster payback and profitability, anyway.-- DrFever, Jul 18 2006 waddabout using the turbine tower as a giant scuba tank to store energy in the form of compressed air? seems like there would be a far greater potential for energy storage in that.-- TIB, Dec 10 2007 Or attach the turbine to a really, really big rubber band... [+]-- sprogga, Dec 10 2007 Bone for trying to make something that is already very energy inefficient, windmills, work in reverse.-- quantum_flux, Dec 10 2007 mabe a fly wheel would work better and store more power then a waght-- loudboy, Dec 10 2007 The flywheel woud be better, though I'd have to run the numbers. Both require a CVT, but the flywheel would be easier to make safe (put it underground). The weight liftting is scary and would add signficantly to tower contruction. This is baked by using lakes and hydro generators which is a remote way of doing the same thing.-- MisterQED, Dec 10 2007 I found this page by Googling because I had the same idea about storing wind energy. My variation is that the weight would not be lifted very far. Instead, it would be a massive weight built into the base of the tower. Imagine a concrete box as the base and the weight inside the box. The cable would not lift the weight directly but would be directed between the weight and the roof of the containing building via a series of (many) pulleys – the effect being to give mechanical advantage to the winch and not require the weight to be lifted far. Also, although a simple governor could control the (clutch?) that transfers power from the turbine to the winch an enhancement would be that this is controlled via electronics and could be remotely switched by a central control room (give each tower a mobile phone and control could be sent via SMS). So, when energy demand is low the towers could be commanded to storage energy, when it’s high they could be told to release their stored energy.-- nick9000, Dec 30 2009 Pulleys would make no difference to the amount of energy it could store. The energy stored is just mass x gravitational field x height.
By gearing it up, you'd be able to transfer momentum to it as well, but that would be lost unless it was used straight away - you may as well just have a flywheel.
Since the towers are already nice and tall, we may as well just make the weights heavier - a good use for depleted uranium, methinks, as it's incredibly dense, and the turbines are normally far away from populated areas.-- mitxela, Dec 30 2009 The idea is that gearing would mean that you could have a larger weight, since it wouldn’t be lifted very far it would be in the base of the tower and not lifted up the tower. Maybe tanks of water - water is heavy and of little environmental impact. I can’t see depleted uranium ever working – it might make sense technically but here in the UK wind turbines are often quite near to populated areas and getting planning permission is tough enough without adding scary words like uranium into the mix.-- nick9000, Dec 31 2009 hmm... water-reservoir towers dot the landscape; maybe put wind-generators on top to assist in pumping the water up: the tower's already there.-- FlyingToaster, Dec 31 2009 Perhaps you could combine energy storage methods: 1) Charge a huge, heavy and cylindrical lead-acid battery. 2) After it's charged, any more excess energy is used to lift the battery up along a tall pole. 3) After it's been lifted to the top of the pole, if there's any more excess energy, it is used to spin the battery. So, that's three forms of energy storage in one, all of them sharing some of the physical components.-- Alvin, Aug 29 2016 Hydraulic acumulator ...
Rather than just pumping water uphill, use high pressure water to lift a very heavy weight on top of a piston. Since water is incompressible, energy losses are modest.
When the energy is required, release the high-pressure water to drive a turbine.
This achieves much higher energy density than pump-storage schemes and can be sited inconspicuously in populated areas, concealed within tall buildings.-- 8th of 7, Aug 29 2016 I like this for its medieval doability.-- bungston, Aug 29 2016 //use high pressure water to lift a very heavy weight on top of a piston//
I'm imagining using a super-soaker to chase an obese person up a ramp...-- lurch, Aug 29 2016 Surely we have enough gravity as it is? It's hardly likely to run out.-- not_morrison_rm, Aug 29 2016 Bees are kept to produce honey, but the deal is that they are allowed to keep some of the honey for themselves (or, in some cases, swap it for sugar).
In the same spirit, I believe that if we don't need all the power being generated by a wind turbine, the surplus should be used to allow the turbine to fly free of its mast, to unshackle itself and enjoy the freedom of the skies for a while. It seems only fair - after all, it must be incredibly frustrating to be one of the world's largest propellors yet remain rooted to the ground.
Once power demands rise, the turbine would return to its roost atop the pole and generate the necessary electricity.-- MaxwellBuchanan, Aug 29 2016 That's what they all said, back in the salad days when gravity oozed off of every mass and could be had just for the cost of being.-- bungston, Aug 29 2016 Aw, quit whining ... you brought it on yourselves. "Free trade !" says the Federation, "Free movement of goods and services !". And then the Ferengi corner the Graviton futures market and you all start bleating, "Oooh, gravity is SO expensive now ...". Losers.-- 8th of 7, Aug 29 2016 Aye, this modern gravity, nowt like gravity when I were a kid...-- not_morrison_rm, Aug 30 2016 random, halfbakery