What is a good replacement for Grana Padano cheese?
Parmigiano-Reggiano is actually a type of grana.
depending on what you are making &/or garnishing, many hard, aged cheeses will suffice. Grana Padano is a slightly "sweeter/more mild" version of Parmigiano-Reggiano, so they have a similar flavor profile.
Grana Padano cheese is very similar to Parmigiano-Reggiano- but is aged much less and therefor is usually less expensive (at least in Italy). It actually comes in there types:
Grana Padano which has been aged from 9-16 months.
Grana Padano oltre 16 mesi which has been aged for longer than 16 months.
Grana Padano Riserva which has been aged for longer than 20 months.
The longer the cheese ages, the more dry and crumbly it becomes and the flavor gets more intense. Grana Padano is still somewhat creamy in texture while Grana Padano Riserva is very dry and crumbly with a full flavor.
So, depending on the recipe- it's quite possible a Parmigiano-Reggiano chefs could work if having the drier crumbly texture and full flavor of the cheese fits.