ABC Analysis: A classification of items in an inventory according to importance defined in terms of criteria such as sales volume and purchase volume. ABC Classification: Classification of a group of items in decreasing order of annual dollar volume or other criteria. This array is then split into three classes called A, B, and C. The A group represents 10 to 20% by number of items, and 50 to 70% by projected dollar volume. The next grouping, B, represents about 20% of the items and 20% of the dollare volume.
Fuel cells (batteries) provide another use option, just as they were utilized by NASA. Fuel cells basically reverse electrolysisâhydrogen and oxygen are combined to produce electricity. Hydrogen fuel cells are very efficient and produce only water as a by-product, but they are expensive to build. With technological advances, small fuel cells could someday power electric vehicles and larger fuel cells could provide electricity in remote areas. Because of the cost, hydrogen will not produce electricity on a
In addition to electricity, fuel cells produce water, heat and, depending on the fuel source, very small amounts of nitrogen dioxide and other emissions. The energy efficiency of a fuel cell is generally between 40â60%, or up to 85% efficient in cogeneration if waste heat is captured for use. The fuel cell market is growing, and in 2013 Pike Research estimated that the stationary fuel cell market will reach 50 GW by 2020.