The cost of each kilowatt-hour of power consumed, each cubic metre of water used and each kilometre over which goods and materials are transported are fundamental factors of operating costs. Knowledge of these factors is then the basis of cost optimizing measures. In the case of compressed air, one of industry' most vital energy sources, only about one in ten users is able to state with any accuracy the cost of each cubic metre. This is hardly surprising as the cost of self-produced compressed air varies greatly with circumstances and is often very difficult to assess. If air is provided as a utility, however, on the principle offered by Kaeser under the name 'Sigma Air Utility', the cost picture becomes much clearer and the advantages obvious.
Users who reject the idea of installing compressors and treatment equipment in favour of buying only the air they need in specific quantity and quality greatly improve the cost transparency of their undertaking. Instead of a complicated calculation to arrive at an approximate unit cost they are presented with a contractually agreed, long-term fixed price per cubic metre from which reliable and accurate operating cost calculations can follow. The base price agreed for the term of the contract covers the cost of providing and running the air supply system as well as an agreed volume consumption per year. A supplementary price for consumption above the base level is also agreed. Metering ensures that the user only pays for what is actually drawn from the air main. The user must provide room to house the air supply system and electrical power for it but the details of the system itself, from assessing capacity needs, planning, design and installation, are all taken care of by the manufacturer's experts. As well as offering cost transparency the air utility concept also contains an automatic unit cost minimising factor. As the air supply system is run and maintained by Kaeser the initiative is there to ensure that it matches most exactly the operating conditions and demand and includes all the most up-to-date, maintenance-friendly and energy-thrifty devices and techniques. Among these is the facility known as Teleservice that provides a data link between the system and Kaeser's Service Centre, where constant supervision by experts ensures smooth and efficient running, rapid diagnosis and rectification of faults and timely preventive maintenance activities. The utility customer also enjoys the benefits of eliminated costs for investment and operating personnel, thereby improving liquidity and freeing resources to be concentrated on core business and generating profits. | 
