I learned two things today about green UX or simply, efficient and fast UX. You can start with your project right now weather they are conscious companies or not.
Minimize the site – so take out all the sections that do not serve a purpose. Condense your home page and link out to pages that go into more detail if the user wants it. This can be done in wire framing before you get emotionally attached to any visual design.
Throw the user a bone – create a Call to Action on each and every section. Don’t let them scroll and scroll with nothing to do! Give them something they can act on – sign up now, free download, read more, view more, give money, book an appointment, learn more, comment, email, follow, sit, lay, play dead!
This is good user experience practices, but it also reduces the time on the site. Time spent searching and reduces frustration! Less time on the site also means less energy spent on the electric grid!