introduction of this fuel cell also contributed to a 9% reduction in diesel fuel consumption and 9.6% reduction in emissions. Legal Requirements for Industries The United States Environmental Protection Agency has set out rules and guidelines for how auxiliary and supplemental power sources (ASPS) that provide secondary power to wastewater treatment plants in case of a blackout. ASPS should be able to supply enough power to run the plant effectively, and be available for start-up in a short period of time in case of emergency. Types of ASPS necessary for adequate power generation include: internal combustion engines, microturbines, solar cells, fuel cells, and wind turbines. ASPS technology is required to be reliable enough to start up quickly, and run for extended periods of time, (i.e. 48 hours or more) with sufficient fuel. Efficiency As previously affirmed, auxiliary power units are commonly used to improve the efficiency of electrical system. The use of auxiliary power units for range extended electric automobiles has been shown to improve the control of energy flow and distribution throughout the system, improving its overall efficiency. For closed systems with extreme power consumption such as tankers and other vessels at sea, the use and quality of auxiliary power systems have a great impact on the efficiency of the overall system. The different uses of auxiliary power for an array of ships and ship activities and how these different power schemes change the overall efficiency and/emissions of the ship's system. Studies have indicated that while ships travel between ports within the same bay, total ship exhaust emissions are due to primarily their auxiliary boiler and auxiliary engine power systems, due to the time and speed required to transit the port waters with the large berth of the vessel. Findings also lead to the conclusion that the power output capabilities of auxiliary engines at a certain point do not increase with the size of the vessel, or the vessel's installed main engine power. There are a great many factors such as machinery variables, power schemes, and size and power of vessels, that there are too many factors to take into account in order to portray an accurate representation of the ratio between main power and auxiliary power output. More surveys and studies should be done in order to achieve this more accurate result. See also distributed generation References Federal Standard 1037C and MIL-STD-180f. Electric power