EVERY goddamn game be it an MMO, single player, idle game, etc. tries to have some sort of P2W attempt to make it more profitable at the expense of the game's quality. It eventually gets worse and becomes "pay walls" and everyone is sick of it. You tread a fine line adding microtransactions to a simple idle game. Big and small companies are ruining their otherwise great games by these greedy actions. You really need to be careful. That said, onto the game!
It needs a calculator. Srsly. Solar panels giving 10.1 heat each surrounding a Generator capable of converting X amount of heat... I'd have to make sure by a calculator, because no amount of the generator's max heat will stop it from exploding. If it collects ANY, it will eventually explode.. so why bother having any heat capacity at all? It creates a huge amount of micro-management. Simply put, if I don't calculate beforehand, everything could explode.
Same for offices and batteries. Why bother having energy storage when office selling power > power produced? Unlike heat though, nothing explodes when it maxes out.
Unlocking and using the next tier of energy or islands is immense. I unlock the coal power only to realize I'd need to upgrade my generators about ten more times. It's a double-hurdle in that it takes time to research and then time to get the appropriate upgrades and money to use them. Then I have to crunch numbers and make sure it's actually worth getting in the first place! It almost seems like the amounts were increased enough to encourage people to buy in for microtransactions. If that's the case, fuck this game.
Surrounding a generator with solar panels in a plus-sign configuration has me confused. With limited tiles to do this, it forces me (the player) to crunch numbers yet AGAIN to make sure no panels overlap and overheat a generator. Then, there's no mention that diagonal tiles don't count... the game says adjacent, which I would have thought it meant all eight tiles surrounding the one in the middle. Again, having the player find this out themselves is counter-intuitive to what an idle game is thought to be.
Researching and using the next bunch of power sources completely removes the purpose of the last one. There is no reason to place any more wind turbines after getting solar panels in place, except in irregular tiles. The difference is too vast. I expect when getting a coal plant placed, solar panels will never be used again as well.
So my advice is if you want MT in a game like this, you need a better game. If I'm going to place a solar panel I'd expect to see little red heat numbers displaying on adjacent tiles and how much a generator can hold vs. what you can place. I shouldn't have to crunch those numbers every time, ESPECIALLY in an idle game. Heck, you don't even have music or sound.. you need to go the extra mile if you want people to throw money at it.
Lastly, the offline bonus ticks are a nice feature I haven't seen in an idle game. I can wreck everything and place research centers everywhere, bonus that shit up halfway, then pause and replace with power producers to make money for the rest. No upgrades transfer to the next power plant, though? WTF? That makes no sense other than to create more of a grind.