Very normal. Here in Europe (well nordics at least) pretty much all the capacity of any wind farm is already sold before construction begins. The PPA (power purchasing agreement) is usually pretty much required to get the loan/funding anyway.

Basically most projects start with the wind company using its own money to find a site and get it approved and then they go and try to find someone to sell the electricity to at a fixed rate before construction begins as selling directly to the spot market has way too much risk for the banks to give loans.

Not sure how different it is in Central Europe with solar as there isn’t much solar up here in the north (just doesn’t make much sense as during the 3 to 4 months in the winter when electricity price is at the yearly maximum you produce effectively nothing)