On a typical Spanish camping you will often be closer to other people than to nature. There are however some exceptions:
Camping Arizitigain in Sunbilla. A beautiful grassy camping. Cycling from Irun to Pamplona it is a good place to prepare for crossing the Pyrenees. There is good food and a small shop.
Camping Camino de Santiago in CastroJeriz. The camping was pleasant to stay and I had some good laughs with the owner who was in funny mood. From the camping you can take a walk into nicely restored village Castrojeriz and there is also a beautiful roman style church which is well worth visiting.
Camping Ciudat de Leon. This camping is situated on a hill with lots of pine trees and shade. The woman who is in charge was very kind and helpful in finding the best location for my panels. From the camping it is about 4km cycling down into the centre of Leon. You will be cycling over what looks like a big motorway, but there is no reason to be scared, it is allowed to cycle there and there is plenty of space on the sideshoulder of the road.
tip: when looking for a nice green camping place Google maps is very useful. First search for 'camping' then all campings in your area will be shown on the map. Next switch to sattelite view and zoom in on the selected camping. You will see how much green there is on the camping and how much open space to put solar panels.