Having been dinged Greenpeace in 2006, when they launched their "Green my Apple" campaign, Apple has responded by making their products more recyclable, removing toxic materials and now proving that they can make fast and energy efficiency computers, too.

Here's what sust-it said: “There’s a staggering difference between the energy consumption of computers in the marketplace; you could save nearly £150 per year on electricity in choosing the most efficient models. We’ve been highlighting these savings through our unique ranking system and it’s great news that Apple has responded to the environmental issues, I hope other manufacturers will follow their lead’’.

The sust-it site is constantly updated and contains a wide range of products from TVs to freezers. You can even switch between electricity tariffs so you can see what other energy providers have in-store and calculate your CO2 emissions at the same time.