I woud like to use this weeks columnn to spread a story I heard las week. Professor Ad van Wijk started his lecture on the e-campus by a story on the simple Dutch doorbell. I think this story encourages to think out of the box and look for sustainability on places you haven't thought of before.

Who ever thinks about the sustainability of a doorbell? I didn't. And of course, a doorbell only uses a small amount of electricity while waiting for someone to ring it. But how often does a bell ring? Twice a day? 5 seconds each time? And the other 86390 seconds it's wasting that small amount of energy, for 7.5 million households. And that's just in the Netherlands!

And the great thing about such small products is that the solution is often small as well. We all know the solar powerd calculators right? Those can be used to power a doorbell that only consumes energy when ringed. This means only 10 seconds of energy usage in stead of 86000!

Since the gains on ordinary items like a doorbell seem so little, they are often forgotten about. We buy A-lable refrigerators and washing machines, but for our doorbell and lots of other stuff such lables don't excist. We shouldn't forget about these small changes which can be applied on a big scale!