The Co-operative Group hopes to save £120,000 and slash CO2 emissions by 722 tonnes each year with stores that shut themselves down each night.
The supermarket chain's 2,200 food stores will be fitted with the "Wake-up on LAN" program that will automatically switch off most machines out of hours.
A total of 1.68 million kilowatt hours of energy will be saved each year using the system, which has been developed by the group's in-house IT team together with IBM.
The system will be up and running by September, when it will control a total of 7,500 till units, 7,500 receipt printers, 15,000 customer and operator screens, 7,500 chip and PIN devices and 7,500 barcode scanners.
The devices are currently left on overnight and the change is expected to prolong the life of the equipment, bringing further savings and environmental benefits.
Mark Hale, director of IS food retail at the Co-op, said: "It is only recently that we are starting to look at energy consumption in IT systems, not just for the green benefits but also the financial advantages that go with it as our estate gets bigger."
The Co-op has set itself a target of reducing energy use at all its premises by 25 percent by 2012.