Executed during years 2010-2013, Cloud Software is a Finnish research program, whose goal has been to significantly improve the competitive position of Finnish software intensive industry in global markets in the field of cloud computing. More than 30 Finnish IT companies and research organizations have participated in the program, and the output of the program has been considerable both in terms of scientific publications as well as industry transformation towards using cloud computing techniques.

I think you'll want to create a watchdog to run on these servers and monitor processor loads, in order to contrast these with the usage logs and assess the size of your required stack. Many cloud hosting services include APIs that allow scaling through a SOA API. Some (I know Azure does) include automatic scaling as an option though.

Beyond that this energy initiative is mostly dependent on your application logic itself. I don't know what kind of volume and complexity we're dealing with as far as the data is concerned, but you'll need to resort to ETL architecture where possible, i.e. where data doesn't need to be actual, in order to cut down processor cycles.