Can someone please, pretty please with sugar on top, explain the point behind high power density?
maybe.
Raw real estate is cheap (basically, nearly free).
not in downtown palo alto. now, you could argue that downtown palo alto is a silly place for an internet exchange. or you could note that conditions giving rise to high and diverse longhaul and metro fiber density, also give rise to high real estate costs.
Increasing power density per sqft will *not* decrease cost, beyond 100W/sqft, the real estate costs are a tiny portion of total cost. Moving enough air to cool 400 (or, in your case, 2000) watts per square foot is *hard*.
if you do it the old way, which is like you said, moving air, that's always true. but, i'm not convinced that we're going to keep doing it the old way.
I've started to recently price things as "cost per square amp". (That is, 1A power, conditioned, delivered to the customer rack and cooled). Space is really irrelevant - to me, as colo provider, whether I have 100A going into a single rack or 5 racks, is irrelevant. In fact, my *costs* (including real estate) are likely to be lower when the load is spread over 5 racks. Similarly, to a customer, all they care about is getting their gear online, and can care less whether it needs to be in 1 rack or in 5 racks.
To rephrase vijay, "what is the problem being solved"?
if you find me 300Ksqft along the caltrain fiber corridor in the peninsula where i can get 10mW of power and have enough land around it for 10mW worth of genset, and the price per sqft is low enough that i can charge by the watt and floor space be damned and still come out even or ahead, then please do send me the address.