Storing Energy in water as heat
Links eco/sunpower/SolarPanel , eco/water , eco/hydropower , eco/BatteryStorage
Calculations Spreadsheet
- E = cp dt m
- cp = specific heat capacity 4.2 kJ/kgoC for water
- dt = temperature difference between water stored and the surroundings
- m = mass of water in kg
- Example1
Energy stored in a 1000 liter water reservoir If water is heated to 90C and surrounding temperature is 20C E = 4.2 (kJ/kgC) x (90 - 20) x 1000 (liter@1kg/liter) = 294000 kJ = 81.7 kWh (1kWh = 3600kJ)
- Example2
How much energy (kWh) to heat geyser of 300l from 15C to 60C ? E = 4.2 (kJ/kgC) x (60 - 15) x 300 = 56700 kJ = 15.8 kWh (1kWh = 3600kJ)
- heat of vaporization of water is 2256 kJ/kg
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