What I understand from the FAQ and Por que usar pages is that this is only a frontend for Google Search which tries to reduce the amount of energy used because of its black background. This idea is not new, there have been previous sites with a black background google search, like Blackle (
http://www.blackle.com/), and even CSS stiles using the Stylish extension for firefox (no need for the extension in Chrome). You can check this article:
http://hubpages.com/hub/How-much-power-do-we-save-if-GOOGLE-...