The 1994 Manufacturing Energy Consumption Survey (MECS) provides data on heat and power consumption by reported end use for about 31% of total energy inputs in the petroleum industry. Based on the available data, the petroleum industry's largest use of energy for heat and power is for process heating and cooling. End uses were not collected for refinery gas and petroleum coke, accounting for the relatively large amounts of data labeled "Not Reported" in the chart below.[MECS 1994]