Data center operators are always looking for the next innovation to streamline operations and reduce overhead. There are operating expenditures (OPEX) that every data center has to incur, such as systems cooling and electricity. These expenses can fluctuate based on a number of variables, including geography. Many data centers are being built in mountain and high-desert states where the cooler, drier climate can reduce cooling costs and where electricity is often less expensive. That is why the newest trend—floating data centers—offers some interesting possibilities.
Google Had the Vision
Google was the first to come up with the idea of a floating data center, and it actually filed a patent for a water-based data center in 2008. The patent indicated that the floating data center would be situated offshore and would use wave motion in order to generate power and would use seawater for cooling. The design included Pelamis Wave Energy Converters in order to create “wave farms.” Google planned to use 40 Pelamis units in order to produce 40 megawatts of power. Cooling would be provided by using a series of sea-powered pumps and seawater-to-freshwater heat exchangers.
Google’s vision addressed the two biggest expenses in operating a data center: power and cooling. In addition, data centers are considered to be bad citizens when it comes to the environment. Data centers consume 10 percent of the world’s power. They continue to be major carbon polluters, and they are coming under additional scrutiny in markets like drought-ravaged California, where water used for data center cooling could be better used elsewhere.
A recent IDC survey of 404 enterprise data center managers (operating facilities of 1,000 square feet or more and at least 100 servers) shows that power and cooling costs are typically 24 percent of the annual budget (e.g. $300,000 out of a $1.2 million operating budget). Data centers’ power usage effectiveness (PUE), which is the ratio of power coming into the data center versus what is distributed across the IT workload, also needs to be lower. A PUE of 1.0 is considered very efficient, whereas most data centers operate at 2.0 to 3.0 PUE.
Google has a reputation for data center power efficiency. Google’s power consumption for non-computing overhead has been reported to be about 11 percent, and the company is said to get about 34 percent of its power from renewable energy sources. Whereas most data centers operate at 30 percent to 50 percent utilization rates, Google data centers operate at around 80 percent.
Nautilus Data Technologies Floats a New Data Center Idea
While Google never actually built a floating data center (although there were many reports that it had), the concept has merit. Another company, Nautilus Data Technologies, has unveiled a floating data center test site in Vallejo, California, that is said to be more environmentally friendly and less expensive to operate.
By using seawater for cooling, Nautilus executives say they have cut the cost of cooling by 40 percent. Unlike other schemes to create data center ships, Nautilus is using a stationary data center model moored in major ports. This eliminates the possibilities of using wave conversion for power, but it certainly cuts cooling costs. Using seawater for cooling also addresses criticism from the State of California that data centers are wasting freshwater.
The Nautilus design uses IT equipment housed in modular data halls on the deck of a barge. Mechanical and electrical equipment, including UPS units and cooling distribution systems, is housed below deck in a watertight hold. The cooling system pumps water from the bay into an intake, filters out sea life and contaminants, and then feeds the water into a heat exchanger, which in turn cools the system racks. By working with the U.S. Navy, Nautilus has eliminated problems from humidity and condensation, and the design uses copper plating and titanium tubing in order to eliminate the effect of salt.
In a proof-of-concept test, the Nautilus system worked as expected, with water temperature returning to the bay within four degrees of the intake temperature. Using five racks of IT gear in order to simulate power densities of up to 32 kilowatts per rack, the system yielded a PUE of 1.045.
The Nautilus approach has some real benefits. In addition to lowering the cost of cooling and creating greater operating efficiency, it also eliminates the cost of real estate and property taxes. A floating data center is also portable and can be towed to any seaside location where it might be needed.
So will floating data centers represent the next wave in IT infrastructure? They certainly offer real advantages. Data center operators are skeptical, because water and IT hardware don’t mix, but the ROI and reduced OPEX of floating data centers are impressive. It seems likely that we will see more floating data centers moored at dockside in years to come.