This portable salt-powered lamp can stay illuminated for 8 hours on a glass of seawater

"Salt powered" lantern? Now my attitude can fuel something! (I know what it really is, I just wanted to make the joke)

How long has this technology been around and why are we just now using it. ,#tiredofthebs

But it DOESN'T run on saltwater. Saltwater is merely the electrolyte. It runs on the anode, a piece of metal that has to disintegrate in order to provide the energy. Also, this isn't a new invention, it's just a battery.
http://www.gmanetwork.com/news/story/545090/scitech/science/much-ado-about-salt-myths-and-facts-about-salt-water-powered-lighting