Yes perhaps Cactus is right.If you are not connected to the main grid,how on earth do they cut you off & then fine you €30,000 Euros?  They may however want to encourage all generators of "non grid" electricity to register themselves with an appropriate authority so that they can levy a TAX (Toll) on them & then those that do not register (If they can be found) would be fined and forced to register for the levy.
It sounds like just another scheme (to add to the many recently set up) for this Spanish Government to GENERATE  ;) more income for itself.