The generation of compressed air is one of the major energy consuming activities in any typical industrial operation. Often ‘Compressors’ are referred to as ‘power guzzlers’ and it is a known fact that only 10 percent of the input energy manifests as energy in the output compressed air. An approximate estimate indicates that around 1500 MW is consumed nationwide just to compress air for industry applications. Moreover, the use of compressed air is seen to be increasing linearly with our industrial growth. This presents a target for the application of energy conservation technologies. Many energy conscious engineers, exposed to factory environments, believe that, at least 10 percent of this can be saved. Therefore, it is in the national interest that compressed air be generated and used with efficiency and economy, wherever possible. This not only results in energy savings, but also a good deal of monetary savings to the company. Compressed air system consists of Instrument Air Compressors (IAC), Process Air Compressors (PAC) and Air Drying units. Lately, Transport Air Compressors (TAG) are also being used for dry ash transport for direct loading into trucks for use in cement plants. The total connected load of compressed air system, in a typical super thermal power plant, would be around 2–3 MW. The contribution of air compressors system in Auxiliary Power Consumption (APC) would be in the range of 1 to 2 percent (the Power consumption of TAC compressors is not included). Though the APC contribution is only 1 to 2 percent, the energy conservation scope in compressed air system would be of about 25 to 30 percent, based on National Productivity Council (NPC)’s experience in a number of thermal power stations

Compressed air is a versatile tool used widelythroughout industry for a variety of purposes. Unfortunately, running aircompressors (AC) often uses more energy than any other equipment. Aircompressor efficiency is the ratio of energy input to energy output. Many aircompressors may be running at efficiencies as low as 10 percent. Improving ACefficiency can yield significant savings to our facility. When talking aboutthe efficiency of air compressors, it is important to remember that thecompressor itself is only one part of the system; therefore, it is important tolook at the whole system when discussing  AC efficiency. Compressed air is the productof a system comprised of the air compressor followed by after-coolers,receivers, air dryers, air storage tanks, supply lines and possibly sequencesand multiple compressor units. The total energy use of a compressor systemdepends on several factors. The air compressor type, model and size areimportant factors in the compressor’s energy consumption, but the motor powerrating, control mechanisms, system design, uses and maintenance are alsofundamental in determining the energy consumption of a compressed air system.