# Question: energy storage is necessary to for example allow solarderived electricity...

###### Question details

Energy storage is necessary to, for example, allow solar-derived electricity to be generated around the clock. For a given mass of storage medium, show that the ratio of sensible thermal energy storage capacity to potential energy storage capacity may be expressed as

R = DEst,t = cDT DEst,PE gz

where DT is the difference between the maximum and minimum temperatures associated with thermal energy storage, c is the specific heat, and z is the vertical coor- dinate for potential energy storage. Considering stone mix concrete as the storage medium, determine the value of R for DT = 100°C and z = 100 m. Which energy storage approach, thermal or potential, is more effective for the parameters of this problem?