The 2nd Data Center Energy Summit taking place on
October 15, 2009 at Netapp corporate offices in
Speaking with Zen Kishimoto, PhD Principal Analyst, Green IT at AltaTera Research Network who edited the case studies, he brought his own insights as he completed the task he faced this year of compiling the results of the case studies (Teresa Tung of Accenture had this role last year): “Like last year, we had a lot of participation and many excellent results. We have fewer completed case studies than last year but will have several additional ones coming soon. One of the studies that attracted my attention was done by Power Assure. It proved the reduction of power consumption by IT gear can be achieved via hardware refresh and dynamic power management… Another pilot is the one conducted at an Intel data center, which measured temperatures at each server and reflected them to the overall floor air conditioning via wireless sensors. This seems to be the first attempt to link the condition of IT gear to the building management system Overall the reported technologies and practices are of high quality and I am sure the audience will find the results highly applicable to their own data centers.”
KC Mares of Megawatt Consulting and co-chair of this event, said: “Worldwide, we spend $23 B as an industry on data center industry annually. That is the equivalent of five major nuclear power plants. Last year’s pilots resulted in an average of 56% ROI for end users. Our goal is to chop away at those huge numbers with our case studies.”
After a keynote speech from NetApp’s CEO, the audience heard
an interview between Jeff Byron, Commissioner on the California Energy
Commission and KC Mares. Jeff said that
This year, I played a background role in the
1. In the new Research Triangle Park NetApp data center, Joe Miller, site operations manager there, said his infrastructure supports 369 IT racks, 1800 engineering racks and 30 engineering network racks. The 360 IT racks run at 6 kw per rack, whereas the 1800 engineering racks run at 12 kw/rack. Custom air handlers for the NetApp data enter enabled them to develop a patented process to enable a cold room and hot aisle . Equipment draws the air where it needs to go, so they don’t need to confine it too tightly. Hot aisle is open return in their pressure-controlled cooling architecture with two sub-systems: one of modulated temperature, and the other is to manage the dampers to modulate the air flow with the controlled fan speed of air handling units dedicated to the cold room. Netapp calls this “cold aisle containment with pressure controlled cooling”. The chiller plant operates at 55 degrees. The air side economizer means the chiller runs fewer hours than conventionally.
Typically if you elevate the chiller temperature, it increases fan power. But as long as it is below 80 degrees going into the front of the equipment, you can allow elevated chiller temperatures. (The most efficient chiller is one that is off, Joe joked) And Netapp tries to keep it down. Cold aisles are contained and hot aisle are open so dampers can fill it out. Cost savings features described above resulted in a $50K per rack build expense rather than $150K per rack, the industry average.
In the event of a chiller failure, there is the opportunity to ventilate. The number of hours that they cannot ventilate is a small risk, he assured the audience
2. Mukesh Khattar gave an interesting presentation on the case study he did at Oracle. He started with the assumption: Variable Frequency Drives (VFDs) are required for hot air containment with any type of enclosure. But do we need VFDs if we don’t have enclosures, he asked of his team. Enclosures do avoid hot/cold spot issues but the cost savings really comes from the FVDs. He said that in a 5K sq foot data center, they managed a retrofit. The estimated cost of the project was $130K. They estimated energy savings of $27k per year, and a utility incentive of $33k. The fan speed went down 50% with dynamic load matching. Oracle concluded that they could avoid the cost of curtains which brought the cost of the project down by $50K roughly. It made the ROI very attractive. One of the unanticipated outcomes is that you could not reduce fan speed below 50% - the fans turn off.
3. Joyce Dickerson reported on a very complex project
4. Pixar did a cold aisle containment case study and with simple blanking panels, panels and curtains, and air-dense foam, and had a payack of 3.7 months on costs to obtain an annual energy savings of $30K. Be sure to read that case study.
5. Ralph Renne of NetApp hosted a case study whose objective was to move their focus from temperature control to pressure control. To ensure that cold aisles will not be oversupplied or undersupplied, Renne concluded that temperature sensor placement becomes crucial. Temperature control does not guarantee that the volume of air is being delivered but pressure control does, and that pressure control also delivered more air into their cold aisle.
Andrew Fanara of the EPA, who attended last year was here again this year because in his own words, “the activity around energy efficiency in data centers is more specific this year, moving away from rhetoric to action. Companies making investments and gaining knowledge are better positioned as the economy turns around. SVLG has to be admired for pulling this event together in a time when most companies were pulling inward and cutting out any “extra projects”, yet as I’ve seen today, there is tremendous activity still going on.”