Energy management is to provide the manufacturing plants with measured analysis of their consumption and costs, and to provide the plants with the information leading to areas where energy saving opportunities may exist.
Energy management broadly involves two aspects-energy conservation and energy substitution.
Energy management broadly involves two aspects-energy conservation and energy substitution.
Energy conservation can be taken to be the reduction in the amount of energy consumed in manufacturing a given quantity of product or providing a particular service. Conservation does not mean reducing manufacturing output or doing without services previously enjoyed: it simply means utilizing available energy resources more efficiently. Energy substitution is concerned with replacement of one fuel by more abundant and /or cheaper fuels. A broad understanding and appreciation of some general principles is important:
- The manner and extent of all energy use should be examined, including the appropriateness of the process/plant items used and the size of the plant item. This examination should, of course, be carried out to the level of details justified by the cost of energy consumed in the corresponding stage of the process. Initially, most effort should be directed towards energy intensive process.
- An essential element of energy conservation is the systematic measurement of plant energy and material flows. consistent units and definitions should be used if measurements and comparisons with other processes are to be meaningful.
- In order to carry out accurate energy and material flow measurements, the use of properly calibrated and maintained instrumentation is necessary. Adequate instrumentation is required for both diagnostic "energy audits" and for the optimum control of energy use during normal plant operations.
- Process waste, such as the production of off grade products, is waste of energy and other important elements of manufacturing cost. Reduction in waste is particularly important where the materials involved have high intrinsic energy contents. Metals, cement, glass, paper, plastics & refractories are examples of high intrinsic materials.
- Much conservation work is concerned with trying to achieve the same process transformation with a lower input of energy, or attempting to increase the amount of work by a given amount of energy input. Most process energy is lost ultimately to the outside environment in the form of heat. The maximum amount of useful work should be obtained at each stage of temperature or pressure reduction in the process. Sources of heat loss should be identified and the process examined to see if the heat loss can either be prevented or recovered for lower grade process use.
- Each individual energy conservation saving should be analyzed to ensure that it does not cause process changes which result in an increase in the overall amount of energy used or detrimental effects in the product or production rate.
- Some energy conservation improvements require investment in new equipment. Investment in such equipment is likely to be inhibited if there is not an appropriate economic framework and guidelines for the evaluation of energy conservation projects.
- Much energy conservation can be achieved by the cumulative effect of many small efficiency improvements. Although it is sometimes possible to identify a few major improvement areas, including many individually small items may be the optimum approach.
