Many measures to save energy in IT require major conversions or new acquisitions. The existing environment also offers room for maneuver.
You can save energy in a variety of ways, even where you least expect it. Above all, more careful handling of resources is required. SAP calculated a perhaps extreme example for a common business application: if you save one CPU second in a transaction, this corresponds to an energy reduction of 10 watt seconds per transaction. If 500 developers each improve ten transactions in this way, which are then carried out twenty times a day by 1.5 million users on 230 working days, this results in energy savings of 95,000 MWh – according to the government’s electricity mirror, this is how much 30,000 two-person households consume in one year.
It is therefore not always possible to see at first glance which effects cause small or large changes. A major change such as offloading resources to the cloud can lead to higher overall consumption because the resulting network traffic causes your own switches and routers to glow. In addition, because the hyperscalers change their hardware every two to three years, the production of the hardware consumes far more energy than the systems ever consume during their lifetime, while the hardware that is now unused is possibly disposed of prematurely and unnecessarily.
So if you are looking for levers with which you can reduce the energy and resource requirements of your IT, you should proceed systematically and carefully. It is advisable to fall back on existing systematics or inventory lists. The classification may also be multidimensional and should not ignore the other requirements to which IT is exposed.
