I read about 50% of a power plant's output is lost as waste heat at the plant. Instead of just pumping water up I wonder if some of it could be airlifted up using large evaporation ponds putting the waste heat to use. Natural solar heating would help too. When electricity is used in the city it also turns into waste heat. Possibly spraying water in a city would reduce the urban heat island effect while increasing rainfall and hydro power downwind. Adding nucleotides to the air would induce cloud formation providing shade and cooling for large areas during the day, and when wanted could provide a blanket effect at night.
Yes “Efficiency” is a relative term. But to my knowledge there is not any conventional power plant near the Seneca plant to try out your idea.
Your evaporation pond idea does have a realationship to something that was actually tried.
Israel built a pond in the desert to make a solar power plant.
It had a heavy brine solution on the bottom and a fresh water layer on top.
The brine on the bottom would get very hot. There were heat exchangers submerged in the brine to carry the heat away. To another heat exchanger that boiled a fluid with a low boiling point that was used to drive a turbine.
Unfortunately I have never heard how well it worked.