The major players in IT, giants such as Dell, Apple and Microsoft, seem scarcely concerned about the environmental impact of their products. Advertisements seldom say that a new computer is eco-friendly, or that it uses little electricity and reduces CO2 emissions. 

That's a pity, because the IT industry is responsible for no less than two percent of all global greenhouse gas emissions. And half of that comes from PCs, whose heat-generating processors need to be cooled: the inevitable ventilator systems are the real power guzzlers. 

Dutch relationship therapist and computer whizz kid Wim de Geus, a resident of Amsterdam, discovered that all the parts needed to change a normal PC into a super-sustainable one were already on sale on the internet. The result: a career change, and a computer that uses 90 percent less energy.