[petre]

Google confused you. One needs 730 kWh to fully evaporate 1 ton of water.

Otherwise it's 1.16 Wh/kg (or kWh/ton) to rise the temprature by 1°C. Thus one needs a delta of 80°C, so 93 Wh to boil a kg of 20°C water. That's what my napkin math was based on. I used that metric a lot to calculate heat deltas in storage tanks.

[fc417fc802]

I think it's the context that's confusing here. Given the topic the first thought is evaporative cooling but IIUC your intention was to give perspective by comparing to a volume of water raised to the boiling point.