Would you like to save 5% per year on your data center energy bill?
Energy efficient servers, virtualization, cloud computing - these are all burning platforms in the green data center discussion. I am not going to talk about these.
However, I do want to bring up a fundamental topic that could have a significant impact on your energy bill – power distribution. Re-thinking site design, as well as considering your many options for power distribution equipment (transformers, switchgear, panel boards and UPS) can yield real energy savings.
Green design philosophies and mission critical facility designs often have conflicting goals. Green designs look to operate equipment at peak efficiency ranges, often near 100% of the equipment rating. Mission critical designs focus on 24/7/365 availability.
To achieve high levels of availability, design engineers are using redundant components... N+1, N+2 and 2N are not uncommon. In a 2N design, power distribution equipment operates at loads of 50% (or less) of the equipment nameplate rating, which may decrease the equipment efficiency. Take a typical double conversion UPS. At rated load, the UPS will operate at 92%-95% efficiency, but at half load the efficiency of the UPS could be as low as 85%.
There are several benefits to a green power distribution design, including:
Increased equipment utilization, operating at higher efficiencies
New efficiencies gained through atypical technologies
Reduced energy usage
Decreased carbon footprint
There are also associated challenges – above and beyond traditional designs:
Gaining acceptance to utilize (or even consider) newer, high efficiency technologies that are not normally applied in mission critical applications
Designs become more complex to achieve the same level of reliability
If you decide the green path is the right direction for your facility, I’ll offer a few simple steps to help guide the process. By taking a little extra time on the front end, you’re more likely to end up with the best (and most cost-effective) solution.
Considerations when developing a new mission critical design:
Define and understand your loads. Make sure you know the average and peak power consumption – not just the nameplate rating.
Once the loads are defined, determine how critical each one is. Does the load truly require uninterruptible power, or can a momentary power outage be tolerated? What about outages of up to 30 seconds?
Develop initial designs, with special attention to the selection of each and every “cog in the wheel” to drive incremental improvements in efficiency. For example, you may consider using a high-efficiency flywheel UPS as part of your power system.
Once equipment has been selected, work with the equipment suppliers to determine if additional efficiency gains can be achieved.
What other challenges do you face? What else can be done to promote green designs?
Please post your comments below.