We are about to buy a house oustide the grid in vallada and would like realistic idea of how much it will cost us to instal a decent solar system that will run the 3 bed house - where can we find informative information and have questions answered - how much, how long, how efficient etc.

well heres link to this site and give them a call
re
http://www.solar-sky.com/

Drop me a PM and I could forward you a note on Solar systems, and a power self assesment chart to help understand requirements.