Dan Golding, 30 seconds, what would each person like to see the folks on other side do to help.
Did anybody mention cogeneration? At least some of that waste heat is turned into electricity which reduces the total consumption off the grid. http://www.polarpowerinc.com/products/generators/cogenset.htm And what about risks? As you increase the active cooling of your IDC, you reduce the ability to survive power outages. This is another reason to separate hot customers from cool. In the event of a power outage, your cool customers who have better heat engineering do not have to share fate with the lazy hot customers. Here I am referring to server customers who do have choices to use more efficient hardware, improve the power efficiency of their software, and do things like server virtualisation to reduce the CPU count in your IDC. The embedded systems industry has plenty of experience in reducing power consumption through both hardware and software improvements. --Michael Dillon