The NREL report notes that, with a supportive regulatory environment, the shared solar market could represent between 5.5 and 11 gigawatts of PV deployment.
See here for the article. Don’t be daunted if there is language that you don’t understand.
I don’t know if that 5.5-11 GW of PV is just for the US, or worldwide, but I’d say that it’s just for the US. A large coal fired power station is around 1 GW (the largest power station in Australia is the Hazelwood power station which has a capacity of 1.6 GW .