Stormy Times

By Dennis Bouley

Private organizations and governments are proposing that all corporations be assigned a carbon allocation. Under such an allocation plan, exceeding the allocation would result in fines and other penalties. With impending government regulation of carbon emissions, the development of an energy cost and carbon allocation strategy will be essential in minimizing the business and financial impact on an organization. Within an office building, the datacenter will most likely represent the biggest source of carbon emissions and wasted energy.

A logical first step, in order to avoid excessive energy expense, is to learn how to measure the datacenter's carbon footprint. Three key variables - datacenter location, IT load and electrical efficiency - impact datacenter power consumption the most and are the drivers for the development of datacenter energy consumption measurement tools.

First key variable: Location

A geographical location that experiences extreme temperatures and humidity levels will consume more energy as the datacenter physical infrastructure systems (e.g., power and cooling systems) work harder to maintain consistent, moderate temperature and humidity levels.

The local source of power generation will also have a major impact on a datacenter's carbon footprint. In France, for example, most of utility generated power comes from nuclear energy. A datacenter in France would have a much lower carbon footprint, from a daily operations perspective, than one located in the Midwestern US. In the case of the US datacenter, the energy source 'mix' may be 60 percent coal, 20 percent oil, 10 percent natural gas and five percent hydro and five percent wind farms. The datacenter in central France would draw 95 percent of its electricity from a nuclear power plant. A nuclear reactor does not emit CO₂ while a fossil fuel burning power plant emits significant quantities of CO₂.

Second key factor: IT load

IT load reflects how much power the IT equipment in the datacenter consumes. The IT load consists of all of the IT hardware components that make up the IT business architecture: servers, routers, computers, storage devices, telecommunications equipment, as well as the security systems, fire and monitoring systems that protect them. The higher the load, the more power will be required and the higher the carbon footprint.

Third key factor:  Electrical efficiency

Datacenter systems have traditionally been oversized in order to build in a fat margin for error in terms of estimating datacenter capacity. Oversizing results in underutilization of equipment that impacts overall datacenter efficiency. Fortunately, new generations of modular scalable IT and physical infrastructure equipment allow for a 'pay as you grow' approach that helps to optimize equipment utilization. Advancements in capacity planning software also allow for much more accurate prediction of datacenter capacities and power consumption. 

Measurement tools

Automated measurement tools, such as the APC by Schneider Electric Data Center Carbon Calculator, Efficiency Calculator, Energy Allocation Calculator and Power Sizing Calculator TradeOff Tools (http://tools.apc.com) can be accessed at no cost and can help datacenter professionals understand how they use electricity, and to recognize how changes in efficiency can impact carbon footprint. Although not precise, these tools do provide sufficient accuracy to allow for meaningful analysis of various 'what if' scenarios.

Entering the data into each of the tools requires some knowledge about the particular datacenter's environment (e.g., number of servers, type of cooling systems, power distribution). In some cases, IT staff and facilities staff will work together to gather appropriate input data. Third parties, such as APC by Schneider Electric, can provide assistance by offering datacenter efficiency assessments that can also provide valuable input to the tools.

CREDIT TEXT

For more information on carbon allocation and datacenter carbon emissions see APC white papers #66, Estimating a Data Center's Electrical Carbon Footprint and #161, Allocating Data Center Energy Costs and Carbon to IT Users available for review at www.apc.com.

Dennis Bouley is a Strategic Research Analyst at APC's Data Center Science Center. He holds bachelor's degrees in Journalism and French from the University of Rhode Island and the Certificat Annuel from the Sorbonne in Paris, France.