Siemens energy storage in rocks vs. the mine

Siemens energy storage in rocks vs. the mine- Upgraded  

Author: David Judbarovski, system engineering, principle inventor

judbarovski@gmail.com, Linkedin

The Siemens scheme is realized by rocks heating of 30 MWh in 2000 m3 of rocks. Their scheme disadvantage is a variability of the temperature after the storage, when input energy varying and its output are unstable. So a block with turbine-generators works unstably, and it decreases their energy efficiency and reliability.  It is two blocks scheme and with underground counter-flow heat exchanger at the rocks being cheap and abundant natural stuffs. The first block is charging circuit for transforming the wind farm electricity in the heat of high temperature, and the second block is steam circuit and its output electricity goes to grid.

The rocks can be heated and store solar energy too, as electricity as thermal onee. In the last case I can recommend two mirrors as solar thermal units of about 1.0 m2 of solar flux each. Planar mirror redirects solar beams on motionless solar dish concentrator, so both its focal spot and whole system of tubes are motionless too.

   

In my turn I offer some more sophisticated scheme, but all elements of it operates in stable conditions not depended on variable input and output and potentially can store 100 kWh per a ton of rocks, is enough for 35 kWh output electricity.

The energy for storage serves to heat our storage stuff can varied its temperature, e.g. from 900 C down to 400 C of cheap and abundant stuff too, e.g. the rocks, soil, slags or any other natural stuffs (sands, clay or so) can work long at high temperature. The said heat by heat exchanger is heating a heat carrier up to about 400 C, then goes with velocity G1 m3/s to a tank B and then G0 m3/s from it goes to steam circuit block with turbine-generators, while their exhaust G0 at about 100 C goes to a tank A together with (G1-G0) from tank B, which level  stays constant and G1 from tank A goes to the said tank B after heating up to 400 C in the said heat exchanger, so the level inside tank B is constant too, when G1 is variable and output temperature after the said heat exchanger is controlled to be constant and equal 400 C, even if variable heat storage temperature.    

Really,

At the tank A : (G1 – G0) + G0 – G1 = 0, so the level in A is constant

At the tank B : G1 – G0 – (G1 – G0) = 0 too, so the level in B is constant