Did you know that about 45% of the energy bill for ICT systems is spent on cooling the equipment?
This became clear in the U.S. Department of Energy (DOE) article, "Database Technology Company Saves $262,000 Annually". The article recounts how Sybase decided to optimize their data center cooling and free up cooling capacity. Working with their local utility, Pacific Gas and Electric (PG&E), Sybase was able to save 2.3 million Kwh, reducing the energy bill by $262,000 a year. The project qualified for three rebates totaling $130,000. The payback for this project is 2.2 years. The Sybase energy managers were driven by:
* Increased growth
* Desire to avoid infrastructure investments
* Reduce cooling system failure risk
* Improve the data center efficiency
* Reduce the mechanical system stress
Sybase has two monitoring systems, one for building automation and a second for the data center. The article states that "continuous monitoring and measurement are a key component to operational success, including verifying ongoing system modifications. The data [collected] is used to discover information technology (IT) and facilities inefficiencies, quantify savings opportunities, justify budgets and measure savings."
Sybase accomplished the increased efficiencies and energy reduction by:
* Installing a high efficiency chiller and cooling tower
* Implementing controls that optimize the load on the chiller
* Increasing the server intake temperature(every 1 degree of higher temperature can save 4 to 5% in energy costs)
* Installing airside economizers that use cooler night time air to chill water in addition to the cooling tower
* Selecting better locations for the floor tiles, closing some tiles and adjusting the dampers. It is better to place a solid tile on the floor rather than closing an air adjustable tile. Closed adjustable tiles can waste 35 cubic feet per minute of cool air.
* Sealing any opening that would leak cool air such as conduits, equipment stands, ramp skirts and cable ways
* Installing Variable Frequency Drive (VFD) fans which allowed the control of air pressure feedback, thereby reducing the required fan power by 83%
* Installing air flow diverters on the discharge side of the racks to focus the high temperature air flow away from other equipment racks
* Eliminate unnecessary lighting with controls that turn off the lights after a 30 minute countdown
The DOE has two tools that are helpful for the enterprise in evaluating its cooling efficiency and energy consumption. The Air-Management Tool is intended for raised-floor cooling with hot/cold equipment aisles. Users will need to complete a data form and answer questions on four data input sheets:
* Air-handler unit data for calculating Return Temperature Index (RTI) (energy metric)
* IT-equipment data for calculating the RTI metric
* IT-equipment intake temperatures for calculating Rack Cooling Index (RCI) (equipment cooling metric)
* Input with questions for determining energy savings and recommendations
The Air-Management Tool will:
* Provide air-management recommendations
* Estimate the potential for reducing supply airflow rate and increasing supply air temperature (higher working temperature = lower energy bills)
* Estimate the percentage of energy reduction for fans and chillers
The DOE "DC Pro Profiling Tool" is a free downloadable software tool for identifying savings for ICT energy consumption. You input description information, utility bill data and system information such as:
* ICT data
* Cooling information
* Power consumption
* On-site power generation
The software then produces:
* An overall picture of the energy use and efficiency
* An end user breakdown
* Potential areas for energy efficiency improvement
* Overall energy use reduction potential
The DOE article has other resources for conducting data center energy assessment (pdf):
* Data Center Energy Assessment Process--use this document as a step-by-step guideline for performing an assessment and determine which DOE tools are available to help with each step
* Master List of Actions for DC Pro--this master list contains many of the energy efficiency actions addressed by the DC Pro Tool Suite that you can copy and paste into a data center assessment report
* Standard Report Template for Conducting a Data Center Energy Efficiency Assessment--this storable document provides a template for the data center assessment report, including the type of data that should be included.
* Master List of Actions for DC Pro--this master list contains many of the energy efficiency actions addressed by the DC Pro Tool Suite that you can copy and paste into a data center assessment report
* Standard Report Template for Conducting a Data Center Energy Efficiency Assessment--this storable document provides a template for the data center assessment report, including the type of data that should be included.
