According to a life cycle analysis of the u. s. food system conducted by the university of michigan, the u. s. consumes 13.9 quads of mostly fossil fuel energy to produce 1.75 quads of food energy annually. a quad is a unit of energy equal to 1 quadrillion (1015) british thermal units (btus). one quad is equal to the energy of 183 million barrels of petroleum. here is how energy consumption breaks down by component in the u. s. food system: life cycle component description of component energy consumed per year (in quads) agricultural production energy used on farms, e. g., fuel, fertilizers, pesticides 2.0 transportation energy used to move food from where it is grown/made to where it is sold 0.5 processing industry energy used in processing food, including electricity 2.6 packaging material energy that goes into making the packaging for food and beverages 0.9 food retail and commercial food service energy used in grocery stores and restaurants 3.9 household storage and preparation energy used to operate refrigerators, freezers, ranges, and dishwashers 4.0 total energy consumed 13.9 source: center for sustainable systems, university of michigan. 2016. "u. s. food system factsheet." pub. no. css01-06. how could these data be best represented graphically?