How about...
1. A way to turn down how many ticks a second so we can experiment and monitor something without blowing ourselves up. Or...
2. An area we can place things for free and it will simulate what would happen in the real reactor area, and it wouldn't provide any money for power sold obviously.
Me: Uhm.. Mr. Penguin uh...sir? That is the least effective way to use that cannon.
Penguin: What do you mean?
Me: well... you are like 2 miles away from that snowman.