Technological strategies for NTT´s telecommunications energy

NTT has been carrying out a total power-up (TPU) campaign since 1987, the objective of which is to ensure profits by increasing revenues and reducing expenses. As a part of the campaign, NTT´s Power Engineers Group has been working to reduce investment and annual costs through energy saving programs and the introduction of decentralized power systems. The target of this power TPU campaign is a 19% reduction in the total sum of electric, depreciation and personnel costs in 1990 compared with 1985. A reduction in energy cost has been accomplished by turning off unused lighting, adopting inverter controls for HVAC (heating, ventilation and air conditioning) systems, optimizing contract power, introducing cogeneration systems, and so on. NTT has been introducing decentralized power systems since December 1987. These systems reduce electric, depreciation and personnel costs; by the end of 1990, decentralized power systems will have been introduced in 50% of all the intended telephone offices