Being able to save energy while using a website is relatively new territory. One of the leading entrants into this field is Blackle - an efficient search engine and an energy-saving website. It is powered by Google Search and owned by Heap Media, in Australia.

The main concept behind Blackle is a black screen that helps save energy. The level of energy consumed differs significantly between a white and black web page. 

The monitors available in the market do not have a constant backlight that allows users to read website content. When a user moves to a white web page, the screen requires a sudden burst of energy to display all the details. With Blackle's black background, a regular monitor would consume lesser energy.

Google is one of the most popular search engines around the world. In January 2007, Mark Ontkush, an American blogger proposed the idea of a 'black' Google. His blog entry had a self explanatory title, "Black Google Would Save 750 Megawatt-hours a Year".

Ontkush provided detailed calculation on how much energy, on average, would be saved around the world if everyone switched to the black version of Google. 

Since then, the creators have been sceptical about the idea, as they were worried about readability of the website. But in 2008, they launched Blackle.

When logging on to the website, one witnesses a black page, grey font and a search box. This is unlike the Google search page, which greets viewers with a bright title.

Browsing through the website, the viewer can find energy saving tips. The tips vary from something as simple as advising viewers to turn off their computer screen when not in use to using motion sensors in rooms that turn off the lights when not needed.

Apart from saving energy, Blackle has attempted to promote green products. Blackle Pages provides a platform for eco-friendly companies to promote their products. 

Viewers can then find them by name, as they would in a directory. Till date, 800 products have been uploaded.

The Blackle slogan sums it all up - "Saving energy one search at a time".