Such events can be avoided by outfitting mission critical devices with an uninterruptible power supply – a solution that is used in settings such as hospitals, computing centres and interlocking installations. It has been estimated that in 2011, around 2.5 gigawatts of uninterruptible power supplies were in permanent operation in Germany, under partial loads, with a mean efficiency of 80 per cent. Hence, in terms of realizable efficiency optimization, carbon dioxide reductions amounting to hundreds of tons annually are achievable.