Energy storage gravity

[Grelinette]

Hello,

It's just a small question to understand the principle of energy storage, and possibly give ideas!

Which energy represents a volume of water of 1000 liters stored at 10 meter high?
(and incidentally, what energy is needed to store this energy?)

On Econology we have already mentioned several energy storage projects:
- rotating masses,
- wagons that go up big blocks of concrete on a slope (post that I did not find),
- Etc. ..
but I have often read that the storage of water in height had one of the best yields, of the order of 80% !.

How is this yield calculated?

There are probably many parameters that affect the calculation, including the performance of the pump that raises the water up, which implies that in the case of a dam where water is stored by gravity ( filling by a river), so without energy, this yield is even more profitable. That said, when we see some pharaonic projects, yet justified by scientific studies, the movement and storage of water seems simpler and more economical ...

But is it profitable for energy produced and unused to be stored in a high water tank?

And from what volume of water storage, this storage is it interesting, for example for an individual dwelling?

I am thinking, for example, of an individual wind turbine running all day, or a roof of PV panels in the middle of the summer, producing energy that would make it possible to raise water on a water point for later use.

Some will probably recall that the most profitable is still to return the current produced and not used in the electricity network rather than running a pump, but in the case of a site not connected to the network (a mountain ecogîte for example) or by choice, one may wish not to send this energy back into the network.

Certainly, thewater is a material that can become expensive and rare, which surely changes the deal, but the rainwater recovery is growing, or simply, in some areas the pools are astronomical volumes of water that are dumped into the sewers. autumn, or in the spring when the pools are emptied for refilling before the summer.

[izentrop]

Which energy represents a volume of water of 1000 liters stored at 10 meter high?

27 wh, not much so
http://enrj.renouvelables.free.fr/energ ... lique.html

the storage of water in height had one of the best yields, of the order of 80%!

Maybe with an industrial equipment ... As an amateur if you get 60% it will be beautiful, like the conversion to electricity and still it must be less than that.

[Gaston]

Storage by pumping water is interesting because the raw material is often available in large quantities and one can "easily" make huge storage (several million m3) without too much danger.

For a detached house, one can consider that a storage of 10kWh is interesting.
So just pump 30m3 water to a height of 120 meters ... or 300m3 to 12 meters

On the other hand, it can be interesting to use the excess energy to "simply" pump water that will be used later, as did the wind turbines of the past by storing the water in reservoirs a few meters away. height to supply the waterings.

[simplino]

Fun to see that gravitation is a weak force rikiki !!

and also that some have forgotten all the basics of energy to their put back in the brain step by step slowly !!
Put a large pool at the top of his house at 12m.

Parts and accessories 1Joule is to force 1m against a Newton and given the earth's acceleration 9,81m / s2 to force in going back from 1m a kilogram weight it's an energy of 9,81Joules !!!
1 Watt is a Joule per second and go up a kilo of 1m / s is 9,81 Watts and 102kilos to 1m per second is 1kWatts !
so since 1kWh is a job of 1000Joules per second for one hour we use 3600s 1000 times Joules 3,6 millions of Joules for less 0,1 € !!!
So 10kWh is 36 millions of Joules actually 36 / 9,81 times of 1 liter of water of 1kg on 1 meter high !!
So we store 1m high 3,67mille m3 or at 12m 306m3 of water !!

The heat of 10kWh in a log is stored in a weight of 2kg of wood, provided you do not lose everything in the open fire!

The heat stored in a mass of 1m3 heated clay soil of 36 ° C in addition (20 to 56 ° C) is 10kWh also, which is why a mass stove must make at least more than a ton !!
In quicklime or other chemical reaction, 10 is stored at 1000 times more like the diesel oil, body fat and petrol 10kWh per liter !!

Finally for lose a pound of fat too much with our mechanical human performance of 20% you have to climb 7200m of altitude without eating anything more !!

So do very intense exercise if you like too much greasy or sweet crap !!

At the rate of one Himalayas a day you will lose a kilo a day !!

[Ahmed]

At a rate of one Himalayas per day you will lose a kilo a day !!

This will be the moment to take the opportunity to raise a big water can to the top: double win!

[chatelot16]

the performance of a water pump has nothing to do with industrial or amateur

the output of a hand pump for well is very good, close to 100% because it is at low speed ... the industrial centrifugal pump output is often pretty shabby because optimized for another purpose, reduce the price pump and no matter what energy is consumed because it is cheap: yes the energy is not yet expensive enough for everyone to save!

to calculate the energy stored in water it was simple at the time when the unit of energy was kg.m: to mount a kg of water of 1m stores 1kg.m

now the iso unit of energy is the joule ... but you must know that 1J = 1N.m

therefore 0,1 kg of water makes 1 N, and mounted 1m makes 0,1 joule

to continue to confuse the joule legal unit is not the usual unit of energy: the usual unit is the kWh: the state and the edf are outside the law by using the kWh

a joule is 1 Ws ... to pass to Wh he has a report 3600 because 3600 s in an hour

[Christophe]

Yes gravity storage by water requires either volumes or high heights!

The formula is simple (raw potential energy stored in joules): Ep = mgh = rho (density) * volume * 9.81 * h either for water 9.81 * v * h or 98100 Joules for 1000L to 10 m or 98 100 / 3 600 000 = 0.02725 kWh is 27,25 Wh as said above ... so almost nothing at all!

I had the chance to fly over the artificial lake EDF pumping revin turbines in the ardennes last year, here are some pictures: energies-renewable / EDF-artificial-lake-of-pumping turbine-de-t13865.html revin

[chatelot16]

the gravity storage of water is good when you have free water and a cheap tank, like an artificial lake

if it is necessary to build the reservoir entirely it is hardly profitable

special case: water table with great depth ... one could imagine a pump of the style pump for reversible drilling also serving as turbine

difficult to economize for energy storage alone, but is this interressant combined with a geothermal heat pump: not only is water used as a heat source for the PAC, but we pump when we have electricity too much and we turbine when we miss it

at home a tank of 50m3 already exists ... the water table is 100m depth: it is 13600Wh ... 13kWh ... finally pikes compared to the price of drilling 100m

[Christophe]

the gravity storage of water is good when you have free water and a cheap tank, like an artificial lake

Uh an artificial lake that costs sweet anyway!

So the ideal is to have 2 natural lakes exploitable ... Obviously it is rare but we find the case in the resort of Lac Noir / Lac Blanc in the Vosges for example!

It was also the first pumped storage station in France (in the world ???): I had already talked about it here solar-photovoltaic / photovoltaics en Ecogite-small-matter-energy-storage-t8225-10.html # p137760

We can also have a lake in height and a water source downstairs provided it has enough flow so not necessarily a lake, I do not know why EDF did not do this in Revin, because we see of course the photo the proximity of the Meuse ... and a beautiful difference in altitude between the natural lake of the bottom ... which would avoid having to build the artificial top.

Maybe a story of too much "flow" put back into the Meuse in the event of turbines?

[Grelinette]

the gravity storage of water is good when you have free water and a cheap tank, like an artificial lake

Uh an artificial lake that costs sweet anyway!

In fact, not that expensive if you do like some farmers: a large hole in the soil with the tracto, the bottom earth put on the 4 sides as edges, then a geotextile felt and a 1mm EPDM membrane ("Firestoneliner", between and 3 and 5 € per m², guaranteed for 20 years). Total cost: less than 4000 €.

Large water reserve

At home, there is a water supply that recovers rainwater from the roofs of buildings. I refurbished it 2 years ago and since it is almost full from September to June. The EPDM membrane is very heavy to move even when folded, but once on site and unfolded, 2 we easily put it.
The reserve is about 15 mx 15 m by about 2 m depth, about 450 m3 of water.

Small water reserve

I had the project to put a wind turbine to circulate this water in closed circuit, filtering it by passing, and by storing a part in height (there is next to it a mound of envion 6 m of high) to have the pressure and possibly operate a device for producing energy.