Cooling down without Air Conditioners

[ShadowHM]

What might have been a better idea is if they found some way to use it to heat water for the city or another heat pump can be used to turn that heat into electricity

That same company does offer steam heating for water-based heating of buildings in winter. Some of the same savings for the corporate users of those services apply, although the company does use electricity to create the steam.

Perhaps they plan to see what effects it has and then use it on larger lakes, where it would take even longer.

Lake Ontario is the 15th largest lake on the planet. And there are not a lot of big cities on many of the larger ones. (None on Great Bear Lake or Great Slave Lake, for example.) This is not a research effort. This is an attempt to provide, as Pete put it, a lesser evil in terms of delivering cooling to those of us who feel they cannot tolerate the normal range of summer temperatures for our climate. That would include a lot of North Americans, no?