Free Energy!! (essentially)

Props to the truck and barter boys for this one:

money quote:
Although expensive to build, solar towers "essentially produce energy for free," said Sherif [a University of Florida professor of mechanial and aerospace engineering].

The Jaloti corollary:
"Although expensive to buy and hang in your living room, a Picasso provides enjoyment and prestige essentially for free"

(I won't even bring up opportunity cost like T&B did . . . )