No love for the Inca? To avoid the diminishing effect of a GPP-modifier, the ability could be changed to a discount for all GP. This way, the discount has always the same impact, independently how many modifiers you already have stacked. IF..... this is possible codewise. I would prefer to let the nuclear plant have its raw production power but decrease it a bit and add the process modifier, something like: +40% production +10% process conversion rate And give the solar plant the specialist focus like: +10% production +3 yields to all specialists -15% GPP cost for all specialsts This way, the wind and hydro plants are for big but simple tile farming cities, nuclear for industrial powerhouses with processes and the solar plant for tall specialist cities.