Note the crack in the ice covering this melt water pool.

Right now hydroelectric power comes from turbines running on liquid water. Here is a different energy source, which we would do well to harness as freeze-thaw cycles increase during climate change. As water freezes, it gives off energy. Better to give it off as mechanical energy than as heat. It also gives off gasses during phase changes.

That is a point at which we can capture energy as well. These would be great technologies for augmenting solar cell technology, which needs more intense sunlight to operate. The two could even be linked.