A previous study by the Department of Energy of 20 metal finishing facilities of various sizes found that annual electrical energy consumption ranged from 3.03 x 10(5) to 1.31 x 10(7) kWh, averaging 2.65 x 10(6) kWh. Annual energy consumption for process and space heating ranged from 3.05 x 10(5) to 1.37 x 10(8) kWh, averaging of 1.58 x 10(7) kWh. While the study was done in 1979, it is believed the energy usage patterns for a plating facility have not changed. The study concluded that the major sources of electrical energy consumption in the average metal finishing facility are ventilation systems, rectifiers, energy conduits (bus and cables), process heating, space heating, lighting, motors, boiler systems and compressors. For hard chromium platers, the order of significance may change, but the categories are similar. Rectifiers that perform the electrodeposition of chromium are a major source of energy usage. In addition, numerous electric motors provide the power to move liquids, heavy loads or compressed air for use in processing. in each facility, electric heaters or steam from a boiler system may be used to raise the temperature of processing liquids to the operating range and a chilling system employed to maintain the operating temperature once it is reached. Electric motors drive pumps in cooling towers to allow for cooling of certain processes. Each rectifier has cables or solid copper bus to deliver DC power to rectified tanks. Because each such conductor has a specific resistance, power is consumed by these passive devices as well. The choice of materials for conductors, the types of connections, the cross sectional area of conductors, conductor design and the cleanliness of connections can translate to energy savings or losses.
