The website Blackle provides a black version of Google.

On the surface it sounds great. “A given monitor requires more power to display a white (or light) screen than a black (or dark) screen,” says About Blackle.

So if everyone turns Google black we’ll save heaps of energy, because it’s such a widely-used website. At least that’s the theory. And Sydney-based Heap Media is getting attention because they’ve created Blackle.

But as always the devil is in the detail… Here are some initial back-of-the-envelope calculations and questions:

  • It’s only old-style CRT monitors which use less energy when displaying darker images. Modern LCD flat-panels use the same power no matter what.
  • Blackle is a front-end onto Google, serving out the adverts and all. So using Blackie adds to the total power consumption. As well as whatever Google uses, you’re also adding in the overhead of routing your requests via Blackle.
  • Currently the Blackle home page claims “122,373.006 Watt hours saved”, up from 113,834.304 Watt hours last Thursday morning. That’s not a lot of electricity. 2kWh is enough to run a small server computer for maybe 4 hours — perhaps 6 if it’s not fully loaded. In other words, Blackle uses 4 or 5 times more energy than it saves.

Still, it’s a great way of getting attention for your business under the banner of “saving the planet”, eh? Plus, having a black background means your site can have that oh-so-current style of having everything look like it’s reflected in some shiny black surface.

Stilgherrian blogs here.