Providing reliable data center backup power

A Tier III data center upgrades its backup power system to provide continuous operation.

By Michael Kirchner, Generac Power Systems, Waukesha, Wis. March 1, 2012

Hosting.com occupies the historical Henry Ford Model-T plant in Denver (see Figure 1). The state-of-the-art Tier III data center provides co-location; hybrid, cloud, dedicated, and managed hosting; disaster recovery; and business continuance services to a global audience.

The data center incorporates Hosting.com’s Smart Design Standards and provides up to 10 Gb/sec of redundant connectivity for bandwidth routing optimization and more than 200 W/sq ft of power and cooling. The fully staffed network operations center uses redundant network carriers, state-of-the-art fire detection and suppression systems, redundant cooling systems, and raised flooring to help keep the equipment cool. A full security staff and sophisticated security equipment, such as cameras, keycard entrances, and biometric scanners, ensure the facility is well protected. 

To say electrical power is critical to data center operation is an understatement. Hosting.com’s Denver facility receives its power from dual redundant electrical utility feeds. The data center ensures that power is always supplied to its critical computer equipment through the use of redundant UPS systems and diesel gensets. To ensure the reliability of its backup power investment, Hosting.com fully tests the backup power system each quarter.

Hosting.com took steps to ensure that it never has to endure a power outage. Based on familiarity and experience with its products, Hosting.com selected the Gemini MPS power system from Generac. Hosting.com’s system features two Gemini units, each of which has two gensets that reside in one enclosure and operate in parallel. The system supplies up to 2 MW of electricity powered by four Volvo 16-liter 6-cylinder diesel engines.

The gensets are controlled by the PowerManager digital control platform and operate within Sound Level II enclosures. The sound level at 23 ft is 73 dB. GenLink communications software allows remote computer access to all data and settings. Twin 400-gal day tanks provide fuel to the gensets and a remote 15,000-gal fuel vault provides backup.

The challenges Hosting.com faced when it upgraded its backup power system involved data center cooling, structural considerations for the cooling equipment and generators, and generator fuel storage.

Square footage in data centers is prime real estate because of the potential revenue it represents. More servers equate to more dollars for data. To provide more space for computers and servers, the backup generators and chillers were placed on the roof (see Figure 2). The electrical equipment was placed on the building’s fourth floor where the data center was located.

The utility supplies 14 MW, 13.2 kV to the building via dual feeds—the only Denver location with this on-site power availability. Hosting.com does not own the facility. In order to provide power to both Hosting.com and the remaining businesses on the campus, it was necessary to split the power feed, which required upgrades to the medium-voltage switches. Discussions with the building owners and utility company representatives resulted in an upgrade plan that satisfied all parties.

The next major challenge was the fuel storage tank for the generators. The original plan was to place a tank in a fenced area in the parking lot. However, local zoning restrictions prevented it. However, using a fuel vault is allowed. The fuel storage issue was resolved to the satisfaction of zoning officials and the building owner, resulting in the installation of a 15,000-gal fuel vault with a duplex pumping system to two 400-gal sub-base day tanks.

There have been at least three power outages since the backup power system was installed in September 2009. The gensets performed flawlessly each time, coming online in less than 13 sec. Hosting.com tests the gensets with full facility-supporting load every quarter, and they have successfully passed each time.

Operating a state-of-the-art Tier III data center requires highly reliable electrical power—without interruption. Because of its reliable and cost-effective backup power system, Hosting.com should never have to endure a power outage.

Kirchner is technical support manager at Generac Power Systems.