How many Power Grid maps do you own? I've found Power Grid gets boring after playing the same map more than a few times.
If I have a complaint with Powergrid, it's that our group has collectively opted into a strategy of delaying the start of phase 2. Sometimes this grinds on interminably such that we skip it entirely, and then enter phase 3 with giant cash hordes and bizarrely high priced powerplant auctions. It's still pretty fun, but sometimes feels a bit broken.
I do wonder if the rules could be tweaked to give some reasonable reward to a step 2 starter.