Our green datacenter cooling system has established a great track record since deployment. Our 2008 total utility costs are projected to come in very near 2006 levels, despite huge growth of equipment in the datacenter.
So, more servers in 2008, but far less power used to cool them. That is green and cost effective! Our growth in power consumption is ongoing, but the trend line has taken a nice step downward due to the investment in efficiency.
For more info on the innovative Bell Products Core4 system at Sonic.net, see this article.