You want to do that with the cooler water that is coming back to the power plant after the heat is delivered to the customer. Thus you use lower value heat to melt the streets. Assuming you do combined heat & power, as a bonus you get a small benefit on the power cycle as you get colder water into the pwrturbine cooling.
The sidewalks are actually the tops of tunnels that carry power and steam in both directions.
When the sidewalks are melted, it becomes waste heat. The rest of the year, it is waste heat. No matter how cold it is, if you accidentally leak heat it is wasteful - even if the side effect is something you may otherwise want.
Idaho summers are very hot. The district heat only runs part time. It is all waste heat from the power plant. There’s ample hydroelectric and wind power in the region as well. I’m not sure if the plant does demand shifting over the course of seasons but it could only run in winter because it runs on biomass and employs students. Many campus facilities are essentially jobs programs for students. The mission is experiential learning. I got a B.S. in business that included welding.
That sounds pretty cool
It was actually a great experience. It’s a land grant university that does a lot of really good research and has solid mechanical engineering, business, law, and architecture schools. I worked several on-campus jobs like janitor and IT support. They set me up with good internships over summers and decent mentors. I wouldn’t be where I am in life without the University of Idaho.