You can't turn around these days without someone asking how green your data center is - and, of course, it's not very green at all, so that's a problem.
The right answer to the pressure, I think, starts with the recognition that you have to deal with the consequences of greenie hysteria without regard to its causes. In other words, your power bill is going up - and what you need to do is find ways to bring it down whether you understand that the whole inflationary binge currently blasting through the economy is ultimately traceable mainly to public subsidization of ethanol or not.
Let's face it, greenies can see global warming on Mars and still blame the coal plant powering their lifestyle - but the reality you have to deal with is one of consequences, not causes; and the most immediate consequence is a monthly increase in your power bill.
But how do you reduce power costs?
I think there are things you can do, and there are things you can usefully ask other people to do.
Externally, for example, you can use your position - especially if you're a big company CIO - to urge groups like SPEC.org to insist that all input power be measured and reported for gear used in benchmarks - and I don't mean calculated numbers on CPU power use: I mean start, stop, and average KWH readings from meters placed between all of the equipment, including storage and networking, and the wall plugs for full run-time durations.
Internally, you know what the usual suspects are: consolidation and virtualization for better server utilization, more efficient cooling or heat recycling in the data center, and so on.
But there's another one too: one you may not want to consider but should: distribute your servers back out to user centers.
A data center you don't have, is a data center you don't get a power bill for - and remember: you originally centralized all those little wintel servers because really there was no other way - but now there is: the software has come a long way since NT4, and a lot of the cost argument you found compelling then simply doesn't apply anymore. So take a long look at what each of those things does: are there opportunities to consolidate some workloads while shifting servers from your power bill to theirs? And when you do that, will the new load in user areas absorb already paid for capacity - particularly on cooling - to produce net savings to the business?
In most cases you'll find that the answers all work out to "yes."
And here's the zinger: just as a lot of the greenie hysteria is just being whipped along to serve unrelated political agendas, you'll find that selling server re-distribution on power costs wraps you in a lovely green halo with a neat super-cavitating effect: enabling you to slide right through previously impenetrable user hostilities to tremendously improve your working relationships with them.
And that's really the bottom line: the search for smart responses to increasing power bills can help empower your users - and that ends by giving you more organizational clout too.