IP: Re: computer and telecom centers get undeserved black eye for power usage

[David Farber <dave () farber net>]

> Date: Mon, 09 Apr 2001 18:26:35 -0400
> From: Matt Oristano <matt () oristano net>
>
> David:
>
> Unfortunately, people tend to get their watts and kilowatts mixed up, 
> especially when they're reporters. Par for the course at the NY Times. The 
> average large scale data center, or Internet Hotel, now is designed for 
> 100 to 300 watts (not kilowatts) per sq foot. A typical data center of 
> 50,000 sq ft is therefore about 10 megawatts of load. A super-gegunda 
> 200,000 sq ft center with all the trimmings might be 50 to 100 MW. Thus, 
> the idea that 46 small scale server farms could average 10MW each is quite 
> reasonable. The equating of 500 MW to 500,000 homes is okay, but that 
> number is probably rising fast. Office buildings in pre-web days were 
> built with 10-30 watts/sq ft, and now the latest high tech offices are 
> being built up to 100 to 200 W/sq ft, not 6 to 8 kilowatts. I think part 
> of the problem is the difference between a kilowatt, and a kilowatt-hour, 
> or power and energy. An internet hotel taking 200 Watts per sq ft, is 
> using 144 kilowatt hours per month per square foot. Engineers throw these 
> terms around interchangeably, and reporters can't keep up.
>
> All of these numbers are from the recent Powercosm show, and from the 
> Huber Mills newsletter, so I trust them.
>
> Some more tidbits: 1) The Silicon Valley power load has increased at 80% 
> (!) per year for the last five years. No matter how many new offices and 
> homes have been built, you can't get anywhere near that number without 
> assigning a lot of the drain to electronics. 2) Con Ed is adding 10 44 MW 
> gas fired turbines in NY just this year. 3) A 2ft X 5ft solar panel 
> generates 100 watts at peak power, with orthogonal non-cloudy sunlight. 
> The average power is more like 50 watts, or 5 watts / sq ft. Probably more 
> like 1 watt / sq ft including weather. A single data center consuming 10 
> MW would need 10 million sq ft (about 227 acres) of solar panels. The peak 
> load in California this summer will be about 50 gigawatts. That's 50 
> billion square feet of solar panels, or 1800 square miles. So, if the 
> folks in CA can just dig into their pockets and buy the state of Delaware, 
> they'll be all set with clean, green, solar power.
>
> Matt Oristano



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