Wind and compressed air

[little b]

is it not possible to use wind energy to compress air in a direct tank (should the wind turbine be oversized?). then release this air according to our energy needs by turning a turbine which generates useful electricity. I like this system which shunts a lot of pollution (photovoltaic, batteries) this system to tend towards an energy self-sufficiency is supplemented by an engine which will run with oil and which will take over if the wind fails thank you for answering me

[Christophe]

If it is entirely possible, systems exist (I do not have one on hand).

But the overall balance will be quite bad (a lot of energy losses in compression and expansion) compared to batteries.

[Forhorse]

Not to mention the danger it represents ...
A small compressor of 100 liters at 7 bars, when it goes crazy, that's enough to kill a man (or several)
Except that there will be more than 100 liters, and much more than 7 bars
Regular control of the tank (s) essential to not have a bomb in power at home.

[Christophe]

Yes a lot of volume and high pressure. You would have to make an estimate volume / bar which allows to store 1 kWh. A motivated one?

Compressed air is not a good vector of energy ... but it can be very practical in certain cases, regeneration of braking on vehicle for example.

[quartz]

A similar system is used on a canary island I think,
before that, the concept was tested in the Pyrenees over 30 years ago.
The mechanism consists in pumping water for the reading in +/- natural reservoirs, then the water feeds standard hydraulic turbines.
The water reserve acts as a buffer accumulator correcting the random wind aspect.
The island is energetically independent.
See topic here, and other details there

[little b]

, but in the case of a bioclimatic house (the energy balance being low) cannot the losses caused by this style of storage be neglected if the energy needs are low then the production of energy (loss included) exceeds needs of the habitat in more clear: it is true that when I collect water with my hands I lose a lot but I have enough left to drink. can this not apply to my house. In addition it is on that it is necessary to maintain the vats to see even having them in a buried room I am sorry for my naivety but I am only a small carpenter who wants to be freed from dependence on energies SALES

[Gaston]

Yes a lot of volume and high pressure. You would have to make an estimate volume / bar which allows to store 1 kWh. A motivated one?

The energy recovered by an isothermal expansion from a volume V2 at a pressure P2 to a volume V1 at a pressure P1 is:

E = ln (P2 / P1) * P * V

For an ideal gas P * V is constant, we can therefore use P2 * V2 (i.e. storage pressure * tank volume).

If we take P1 = 3 bars (= 300000 N / m2) and P2 = 10 bars (= 1000000 N / m2), we get E = 1.2 10 ^ 6 * V2.

To store 1 kWh = 3600000 J, a 3 m3 tank is therefore required.

Hence the importance of using much higher storage pressures ... with the resulting problems.

PS
With adiabatic relaxation (more usable in practice), we recover less energy ...

[dedeleco]

isothermal relaxation

very difficult to do, except very slow relaxation and therefore we recover less, and a lot of cold that freezes everything.
With the water, stored at height, even more voluminous (swimming pool at the top of the hill), recovery with a turbine is easier and better !!

Otherwise we systematically forget the large spring motor storage which is comparable and also simple !!!

We better measure that oil is a compact and inexpensive energy !!

[Forhorse]

Leaving to leave on dangerous storage solutions, why not store in the form of hydrogen?

[little b]

thank you for all these details so if I recapitulate it is better to remove the compressed air