If you don’t measure, you don’t have control over energy efficiency

A green baseline is critical if IT leaders want to transform their IT estate, reckons analyst Forrester. Its new report, “Is Green IT Your Emperor with No Clothes?” argues that what you can’t control you can’t measure. In other words, if you don’t know how much power a PC consumes, or what the cooling costs are for your data centre, you will struggle to create a strategic plan to reduce the footprint of either.

The analyst asserts that IT leaders must drive the green agenda forward and cannot rely upon vendors. They must inventory IT assets, estimate their annual energy consumption and CO2 emissions, and estimate the costs of operating all the equipment.

An inventory is a good idea: it will let you know if your data centers are optimized and how many laptops sit unused. Once all the switches, routers, servers, printers and so on have been catalogued, you can estimate their energy consumption from the faceplate or ask the vendor directly. Use of PC power management software can tell you how long the PCs have been on and it’s simple enough to track the usage of printers. The equation is pretty straightforward:

(Number of assets) x (Energy draw, in kW, per asset) x (Annual uptime per asset, in hours) = Annual energy draw in kWh

Gather these figures together and you will have a Power Usage Effectiveness (PUE) and Data Centre Infrastructure Efficiency (DCIE), the figures promoted by the Green Grid for gauging data centre efficiency. Only when you have a baseline for IT energy efficiency can you create a plan for increasing the efficiency with tangible results. The kind that finance directors like to hear.

There is an interesting article on creating a green IT baseline here:
http://weblog.infoworld.com/sustainableit/archives/2008/09/green_it_baseli.html
and you can find the Forrester report here: http://www.forrester.com/Research/Document/Excerpt/0,7211,46597,00.html