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>Heating the equivalent of 1 gallon of water from -60°F to a reasonable liquid distribution temperature (50°F) means heating it up by a whopping 110°F. That’s 268 watt-hours of raw energy required just to bring a single gallon of water up to distribution temperature!

It's actually more than this, because the phase change from solid to liquid takes a lot of energy too.

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Yes, this bothered me too. It's impressive how much energy is required to just melt water much less bring it to temperature. It's 330 kJ/kg, which is 1250 kJ/gallon: 350 Wh. So it costs more energy to defrost one gallon of water than it does to do the rest of the 110F temperature change.

The physics term for this is the "latent heat of fusion," or the energy required to change states from liquid to solid, or vice versa.

A few years ago I saw someone calculate the energy required to melt the ice in front of a locomotive (I think) at speed; IIRC it required a (not small!) nuclear reactor's worth of energy. Not practical!

> A few years ago I saw someone calculate the energy required to melt the ice in front of a locomotive (I think) at speed; IIRC it required a (not small!) nuclear reactor's worth of energy.

Sounds like https://what-if.xkcd.com/130/.

fixed, thanks!

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