Cloud companies have placed their data centers in cold climates — even inside the Arctic Circle — to more easily cool their computing gear. Startup TeraCool proposes that data centers tap into another source of free cooling: liquefied natural gas storage tanks.
Cambridge, MA-based TeraCool has developed a system that marries a source of unwanted heat — data centers — with the largely unused cold available at LNG terminals. With sufficiently large capacity at an LNG port, the company calculates that a data center could cool itself from the surplus cold that’s produced while turning stored liquid gas into pipeline-ready gas. With additional equipment, TeraCool says it could also generate power on-site.
So far, it hasn’t found a data center operator willing to give its novel cooling system a try. But CEO and co-founder Bob Shatten argues that the technical risk is low because capturing cold from LNG terminals is already done for other purposes, such as producing industrial gases and for freezing food. TeraCool’s innovation is applying this method to data centers, which typically spend at least a third of their energy bills on cooling.
To liquefy methane gas, it is cooled to minus 162 degrees Celsius, or minus 260 Fahrenheit, and then stored in insulated tanks. To put the liquefied natural gas into pipelines, it is heated, either by burning gas or using seawater, which turns it back into a gaseous state. This vaporization process produces a significant amount of cold — called refrigeration capacity in the industry — that could be used for practical purposes.
The TeraCool plan calls for heat exchange loops between a data center and an LNG terminal (see diagram above). The heat from the data center, captured and transported in a liquid, would be used to vaporize the LNG. Then the excess cold from that process would be sent, again via a working fluid, to the data center to cool the equipment.
A system could be configured to generate power as well, although it would add significantly more to the cost. A portion of the cold working fluid from the LNG tanks could be expanded with the heat from the data center to vaporize it. The change in pressure from that expansion process can drive a turbine and generate power, says Teracool chief technology officer J.D. Jackson.
Shatten calls the concept an example of “industrial ecology,” or the study of material and energy flows to optimize the use of natural resources. The company’s founders came up with the idea when Shatten did an environmental assessment of an LNG port near Boston and found that its operators were looking for a use for the cold they generated. He thought of pairing an LNG terminal to a data center “because they typically run around the clock so it’s a good match for taking advantage of the wasted energy,” he says.
There are about 100 LNG ports around the world and the company estimates that its system is suitable in about a quarter to a half of those, particularly in hot climates. A large data center next to an LNG port with sufficient cooling capacity would justify the cost of the cooling system in less than two years, Shatten says.
On paper, the company’s technology saves lots of energy and would lower the environmental footprint of power-hungry data centers. The biggest challenge for TeraCool’s energy-saving system is simply finding a company willing to give such a new technology a try. Also, data center operators may balk at co-locating at an LNG facility, which could pose more risk than, say, building a data center in a rural location near farms. (TeraCool notes that there hasn’t been a major accident at an LNG terminal in the history of the industry.)
Even with low technical and safety risk, data center operators that rent out space to corporate clients wouldn’t make this sort of leap simply because the approach is so unusual, says Michael Levy, an analyst at the 451 Group. “I believe that this solution would be too progressive for a multi-tenant operation,” he says. “However, there is a great opportunity for TeraCool with mega scale Web 2.0 single tenant datacenters from the likes of Google, Facebook, eBay, Twitter, Yahoo, etc. Furthermore, these facilities tend to be larger, which is required by TeraCool’s business model.”
TeraCool executives are in discussions with multiple companies and note that it can take years to choose a data center location. CEO Shatten is confident somebody will try the cooling system because of the energy savings and environmental benefits. Given that a significant amount of the world’s energy is consumed in data centers, perhaps some radical ideas are worth considering.