On a smaller scale, you can use several gallons of water as a thermal buffer ("battery") for a greenhouse, grow tent or small room. No, it's not convenient to have gallons of water around, but it can be useful for growing things that need to stay in a specific temperature range over the course of a day.

For example, I'll be doing this for my mushroom grow tent as we get into winter here. (Lows of 35°F up to 80°F during the day.) Mycelium development and/or fruiting is partially controlled with temperature.