kJ/K
kilojoule per kelvin
Heat capacityexact by definition
The kilojoule per kelvin is a thousand joules per kelvin, the convenient size for tanks, thermal masses and building elements. A 300 litre buffer tank of water has a heat capacity of about 1256 kJ/K, so storing 20 K of usable swing in it holds about 25 MJ, or 7 kWh. The factor of 1000 is exact, being a decimal prefix.
| 1 kJ/K | 1,000 J/K |