Just adding green power to be green is not a solution; and just not good enough.
Making your datacenter green is more as only buying green energy, this is why we started the other way around; we first looked at how we could make our datacenter use less energy, we where able to save 45% by implementing new technology and only after this implementation we also switched to green power.
Because we believe in green energy; it does not mean we should just abuse the green energy resources we have.