I think the big clients (google, facebook, et. al) are getting smarter very quickly now (see for instance cd34's link above). It also requires not just one pers

I think the big clients (google, facebook, et. al) are getting smarter very quickly now (see for instance cd34's link above). It also requires not just one person, but a whole team of smart architects, engineers and environmental experts to figure this out for every individual server centre. Also - some of the big successes (heat sharing, using water from outside sources, etc.) also require government involvement, which can be a minefield in itself (note: google seems to have much better success with these government schemes in Europe than in the USA).