The British duo missed out on their second world title together as they finished just two points behind perennial Brazilian rivals Robert Scheidt and Bruno Prada, despite leading going into the decisive medal race.
"It's frustrating that we weren't able to finish it off, but this is just a battle, not the war," said Percy. "It provides great motivation for the weeks ahead."
Meanwhile, Olympic champion Paul Goodison concluded his Laser World Championships in Boltenhagen ranked 20th overall after being on the receiving end of three yellow flag penalties from the jury for adjudged illegal kinetics of the boat.
"It's been a pretty frustrating regatta for me in terms of the yellow flags early on, which I have to say I've been a bit surprised at," said Goodison.
"I don't feel that I've been doing anything differently in my sailing to justify them, but obviously the jury at these World Championships has seen that differently.
"In spite of those issues there were some positives to come out of the week, so I will have to take what lessons I can from this event forward into Skandia Sail for Gold and the Olympics."