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Get Moving on the Green Closet

A lot of attention is now focused on IT and data center electrical power consumption. It is also time to include the LAN closet in the IT energy conservation plans.Applied Research performed a survey for Symantec that polled 1,000 IT professionals. The goal of the survey was to determine the attitude and efforts relating to energy conservation, i.e., green IT. The results of the survey, "IT Management Slideshow: Trends in Green IT" are here.

Here are some of the highlights of the survey which demonstrate a change in attitude as well as increases in the efforts to reduce electrical energy costs:

* 97% would replace old equipment with more energy efficient devices.

* 64% said they would pay at least 10% more for these devices.

* 33% said they would pay 20% more for energy efficient devices.

* 94% monitor power consumption. I think that although monitoring occurs, it is not real time and the reaction to the power bill is often delayed. The monitoring should also lead to more aggressive procurement actions, with energy costs factored into the decision. Two years ago almost no monitoring occurred. This is a change for the better.

* 94% have performed server consolidation and 93% have implemented server virtualization. This appears to be true because the server market sales have slowed considerably. However none of this reduces the energy consumed in the closet.

* 67% are working on or planning an energy conservation strategy, but only 30% have a strategy in place.

* 92% listed energy conservation as a goal and 91% listed cooling reduction as goal.

All of this sounds good, appears to address the nation's growing energy crisis and will at least stabilize if not reduce the IT energy costs in enterprise, government and education. IT data center managers are looking for a 25% reduction in energy costs, which is definitely possible with the right strategy implemented.

My focus is on the closet. A closet is not large in its floor space but if there are many closets, their total combined floor space can exceed that of the data center floor space. The utility industry reports that 1 square foot of a data center consumes 575 kilowatt hours of electrical energy per year. About 50% is used to power the equipment and 43% is for cooling that equipment. The remaining 7% is for lighting, signs etc.

Electrical rates vary state by state and the rates vary by location in the state. The Department of Energy publishes the state power rates several times a year. The table below shows the energy costs for January 2008 and January 2009. The average national cost increase in one year for electrical power was 10%. This is not an anomaly. IT should expect similar annual rate increases in the future. One eastern state utility is proposing a 72% increase in rates in one year. So IT has to pay attention because the utility bill is becoming the second biggest expense item.

So let's look at the impact of these rates on a data center then apply them to a closet.

Let's apply the same analysis to a LAN closet and assume that the closet has 1/4 the IT equipment density of a data center floor. Also assume that the closet has an area of 10 X 15 feet or 150 square feet. Then 575kWh x 1/4 would result in 143 kWh/year consumed per square foot of closet space.

The cost per closet does not seem to be high except--how many closets exist in today's enterprise, 10s, 100s? The total energy bill could equal or exceed the cost to operate the data center if many closets are involved. 200 closets could cost $345,000-$772,600 a year to power and cool.

So here are suggestions for reducing that closet power bill:

* You can cut the power requirements by 40% to 60% by buying energy efficient LAN switches.

* Use class 2 IP phones and avoid class 3 IP phones.

* Have a LAN switch support LLDP or CDP that delivers the required power in .1-watt increments.

* Use energy saving software in the LAN switch to turn off PoE devices nights and weekends.

* In some LAN switches, just plugging in the cable without a device at the other end will drain power so do not connect the cables until necessary.

* 1GBE interfaces consume more power than 100-Mbps interfaces, as do 1GBE IP phones.

The expansion of PoE in the closets and the new IEEE standard 802.3at will only exacerbate the closet power and cooling issues.

When you reduce the electrical power consumption you also reduce the cooling bill. For every 1,000 watts of power reduced, you save 860 watts of cooling power. So what is now apparent is that if the IT department includes the closets in their strategies for energy conservation, then there will be commensurate savings as well.