While I sort of agree that VAT exemption is a sort of subsidy it's important to remember that all other power generation typically receives the same "subsidy" because it's done by companies which don't pay VAT.
I see, but the grid operator has to collect the VAT for every kWh from the customer. I don’t pay VAT for my balcony PV and also not for the energy I get from it. That is not parity, I as a producer have an advantage here.