We recently noted how American College Testing's use of a geothermal cooling system boosted the energy efficiency of its data center in Iowa. Another new midwestern data center operator has now announced plans to pursue a geothermal cooling system for its project in Nebraska.
Prairie Bunkers LLC said this week that it has completed a test well for a geothermal cooling system at its 760-acre Prairie Bunkers Data Center Park near Hastings, Nebraska. The successful test of a vertical closed-loop system paves the way for the company to offer geothermal cooling for its innovative project.
Prairie Bunkers hopes to convert dozens of World War II ammunition bunkers into data centers, hoping to capitalize on interest in ultra-secure data storage. The company says its plans for geothermal power will help tenants achieve Platinum status under the the Leadership in Energy and Environmental Design (LEED) rating program for energy-efficient builfings.
"Prairie Bunkers is pioneering the use of geothermal cooling to reduce electricity usage in one of the most power intensive industries in the nation," said Pam Brown, CEO of Prairie Bunkers.
Growing Niche for Data Bunkers
The Nebraska project is part of a growing niche for underground nuke-proof data bunkers housed in former military facilities, mines or limestone caves. Although security is usually the primary motivation for customers, underground facilities offer advantages to the data center operator, including using the earth for improved cooling.
Like the ACT project, Prairie Bunkers plans for geothermal cooling feature a system of vertical holes drilled into the earth’s surface which house a closed-loop piping system filled with water and/or coolant. The cool earth allows the underground piping system to serve as a heat exchanger.
500-Foot Test Well
Prairie Bunkers hired geothermal specialist Leuck’s Drilling to drill the test well and develop plans for a complete geothermal system for the project. "The geology of the Prairie Bunkers’ data center site is ideal for geothermal cooling,” said Jenny Leuck, founder of Leuck’s Drilling. “At a depth of 500 feet, the test well at Prairie Bunkers is the deepest and best geothermal well out of the 29 commercial geothermal projects we have handled in Nebraska and the Midwest."
“The geothermal cooling system will convert the average ground temperature of 55 degrees at the site into 'free cooling' that will reduce the power usage and electrical costs for a typical data center in our park by 30 percent," said Keith Wilkins, President of Great Plains Data Center Builders, a partner in Prairie Bunkers. "We start with very low electrical rates, so a 30 percent reduction in the largest expense translates into one of the lowest operating costs for any data center site in the U.S."
Prairie Bunkers is developing the project on a build-to-suit basis. Non-traditional projects can be a tough sell in an already tough market, but the company believes the cheap power and energy-efficiency offered by geothermal cooling will prove to be key selling points.
Leading With Power
Wilkins says Prairie Bunkers can offer power pricing that averages 4 cents a kW hour year-round. The company is offering to convert 184 World War II naval ammunition storage bunkers into data centers, which can be customized from 1,500 square feet to 25,000 square feet, with power allotments ranging from 500 kilowatts to 8 megawatts.
Prairie Bunkers also says its facilites can achieve Platinum LEED certification for client who want it. Underground data centers can’t receive LEED certification, but Prairie Bunkers executive chairman Gary Hultquist says that restriction doesn't apply to the company's project. "Because our bunkers are above ground, albeit insulated on three sides and top by prairie earth and grass, we are advised that they can be LEED-certified," Hultquist told us recently.
Prairie Bunkers is a partnership between San Francisco firm Hultquist Capital and Great Plains Data Center Builders, an Omaha-based engineering firm that has built more than 70 data centers.