The main point is , is it possible to install pressurized caves every where? there is enough caves around the world so it can be a real solution to store electrical energy.
It is obvious that storage of electrical energy is one of the biggest challenges in the world as storing energy is the only way to full use renewable as main energy source. So indirectly solving the problem of storage will solve the climate change as there will be no need of fósil fuels to produce electricity.
It is not clear which is the solution, there si many proposed: Hydrogen, Caves, lithium batteries, hydroelectric reversible centrals,
This is an article where you can see different ways: http://discovermagazine.com/2015/july-aug/26-power-stash
My favourite is to not to store that much and make grids whit active control of the demand based on the real time electricity price market, where the electricity price changes based on the renewable sourced dispensables and the companies an households are smart and works when electricity is cheap.
This can be added to the idea of store on the electric cars so those are used for mobility and grid support.
What do you think about that?