We have two 135 watt panels mounted on articulating arms and one 65 watt above the custom boom gallows.  With the panels on the articulating arms we were able to floow the sun all day while at anchor and never used the engine to charge the 400 amp hour battery bank.  Our blog has more info and many photos.

http://www.captainmontgomery.com/2009/07/westsail-32-stainless-steel-fabrication.html