World energy supplies are often measured in the unit of quadrillion British thermal units (10^12 Btu ), generally called a "quad." In 2015, world energy consumption is projected to be 5.81 x 10^17Kj . The use of the British thermal unit (Btu) is common in much engineering work. (1 Btu = 1054J) A BTU is the amount of heat required to raise the temperature of 1 Lb of water by 1 degree . How many quads of energy does world energy consumption quantity represent?