petajoule (Pj) The largest producer of energy: in 2001, the USA produced 75,295 petajoules of commercial energy, inclueding solid, liquid, and gaseous fuels; as well as, primary electricity. A petajoule is 1,000,000,000,000,000 joules. —Guinness World Records 2005; Special 50th Anniversary Edition (1955-2005, 'The environment'),Guinness Wor...