Electricity in Spain
The Spanish domestic power system is 220 or 225 volts AC.
Standard continental two pin plugs and three pin plugs (with earth) are used. A two pin plug will fit in a three pin socket.
Americans with 110V equipment will need a transformer which can be purchased at most ironmongers while the British will only need a plug adapter which is easy to find and, if all else fails, can almost always be purchased at the airport.