Efficiency indicates how well a UPS system converts input into output (Efficiency = Output Power ÷ Input Power). The higher the efficiency, the more the UPS system will save in operating costs. Tripp Lite SmartOnline Single-Phase UPS systems — unlike most similar competitors' UPS systems in its class — offer two levels of efficiency for two levels of cost savings. When the UPS is in Economy Mode, its inverter is off during normal operation (saving energy). When needed (during a blackout, for example) the inverter will switch on automatically. When the UPS is in On-Line Mode, its inverter is on continuously. The difference between the two modes is a matter of user preference. Both modes are highly efficient, and both modes provide a high protection level. Managers can manually switch between modes using the UPS control panel or can remotely schedule mode changes through PowerAlert software (perfect for applications that have less critical operations running during evenings or weekends).