JWE1 had an upgrade for power stations, "Reduced Upkeep" which reduced the costs of power stations. Back then it was not something that I used, as it was easy to make money, and the upgrade could be used for outage protection and improved output instead.
After some time with some parks made in Custom Challenge mode, I could actually see the upgrade be more useful.
Power stations could only ever have two upgrade slots, and there are only two forms of upgrades available. Improved output would always be useful, but the weather protection never really felt like a useful upgrade to me from my experience with the game. I would very much like the option to reduce the upkeep costs of the power stations in my park as they could start eating up a good portion of my upkeep the larger the park gets.