The IT sector has discovered a theme fitting to what has in many places been a mild winter: the power consumption of computer hardware, the high cost of cooling down the heat generated in electronic data processing centres and the negative effect of the sector's high energy consumption on the environment. The Internet uses a great deal of electricity. It is said to use as much worldwide as the amount produced by 14 power plants, and its CO2 emissions are almost on a level with those produced by air travel. In addition, the amount of data produced and processed is constantly increasing. Large electronic data processing centres are the factories of the information age. At present there are some three million such centres worldwide, and the number is increasing. Now more and more Internet companies are focusing on energy-saving solutions. Systems providers like Rittal, a German firm, offer such solutions. A report by Michael Wetzel.