Actually if you situate the system at places with higher electricity cost or higher temperatures it makes even more sense (not for Bitcoin mining though, where you try to keep electricity costs low).

The DataTank PUE is 1.01 (less than 1% of electricity for cooling) in cold or hot climates. While the average PUE for air cooling is 2.2 (120% ! of extra electricity for cooling) in hot and humid places like Hong Kong. Immersion complete new possibilities in the choice of locations.

The reason why the first phase is at $0.02 in Washington State is Bitcoin mining. Having said that, not being limited to cold climates means you now have a lot more places with cheaper electricity where you can mine. Example: cooling a mine in the the Caribbean can be a challenge and expensive with water or air cooling, for immersion it's no different than being in Washington State or in even hotter places. Same same. South East Asia is another example.