This study evaluates the electrical energy use patterns of 2 Nigerian food and beverage industries (FBI) over a period of 4 years (2010-2013) with the aim of developing an index that measures the energy efficiency of producing a finished product. The data used for the study consist of monthly diesel consumption (liters), electricity consumption (kWh), the mass of finished product (kg and unit mass energy content of finished product). Some of the findings reveal that diesel generators account for 87% and 89% of electrical energy needs of industry A and B, respectively. This is in an effort to ensure uninterrupted power supply for production process. The average electrical energy use index for industry A is determined to be 0.70 while that of industry B is 0.76. These values indicate that neither of the industries efficiently utilized electrical energy for their production processes. The inefficient usage of electrical energy for finished product is attributed to the usage of inefficient electric motors, non-compliance to the usage of energy saving equipment and diesel leakage from generating sets.