You can drive up to departures for set down only.
You cannot park there and wander away from it.
Just use the car park, it doesn't cost that much.
Otherwise you'll be blocking the set-down area.
You are likely to be towed.
You can do this, however try not to have to wait too long as there are airport police constantly moving people on. Be prepared to have to possibly move off and come back around again - I had to do this 3 times last week!
If you're a tad early, might be a good idea to park up somewhere, e.g. the petrol station and get your friend to text you once they get their bags. Then he/she'll be there waiting for you as you drive up!
Area 13 the far side of the short term car park works better for me. Even if you have to do laps it is much easier to see the person you are collecting as you go by.
There is also a €1.50 30 min parking rate available for collections.