Liquid Gas Plants Could Power Data Centres For Nothing

An ingenious proposal to locate data centres near liquid natural gas (LNG) plants could provide all their cooling and electrical power for next to nothing – and the group behind it hopes to interest European providers in the concept.

Natural gas storage plants produce excess refrigeration, and waste enough energy to run a data centre according to TeraCool. The plan is being looked at by LNG plant owners in several countries, and has won the Audacious Idea prize in the 2013 Green Enterprise IT Awards 2013 from the Uptime Institute.

Free energy from gas plants

Natural gas is typically liquefied at the places where it is extracted from the ground, by condensing it at temperatures around -160C. It is then transported in liquid form in tankers to LNG plants where it is stored in giant cryogenic tanks. When needed, it is turned back into a gas (vaporised) for circulation in the gas supply network.

Liquid gas stores energy, and the vaporisation process releases that energy, while also producing very low temperatures. However, this energy and cooling normally go to waste, because LNG plants are situated away from population centres which could use them.

“We think there is a tremendous opportunity,” Bob Shatten, president of TeraCool, told TechWeekEurope. “We have had interest from some LN G terminals – now we need to get the data centre world to step outside of the box and align their interests at one of these locations.”

TeraCool proposes that data centres could be built near the LNG terminals – as long as there are good data connections, and improve the energy efficiency of both sites. The waste heat from the data centre’s servers could help vaporise the gas, and the energy released could power the data centre.

“The system adds an additional refrigeration loop to the circuit in which the refrigerant is pressurized, warmed and vaporised,” explains the Institute’s citation. “The expanding refrigerant can also drive an expansion turbine coupled to a generator to produce electricity in a combustion-free, emissions-free process.”

LNG plants are often huge, and some could easily provide enough power for the largest data centres ever built, said Shatten. “The upper bound for data centres is around 90MW in the US – and one terminal we looked at in Seoul, Korea, has 22 storage tanks, and could provide 350MW of cooling and 87MW of electricity.

Since a 90MW data centre, operating at a PUE efficiency figure of 1.3, would only need around 27MW of cooling, that’s easily enough.

The limitations of the idea are the variation in the amount of gas being vaporised. The data centre would only be able to rely on the steady output of the plant (the “minimum gas sendout”). However, as Shatten points out, gas is a transition fuel from coal, and is increasingly used in generators which power the base load of countries’ national grids. As a result, many new LNG import terminals are being built ot proposed worldwide.

European data centres are migrating northwards to some extent at the moment, to countries like those in the Nordic region, where cooling can be had for nothing from the surrounding air. Co-location with LNG plants could be particularly useful in hot countries in Southern Europe, like Spain and Portugal, where cooling is harder to come by.

“Once this happens, it will happen fast.” said Shatten. “The data centre has very little to lose by trying this – it can get its money back very quickly on the energy savings. ”

Uptime Top Ranking

The other Green Enterprise IT awards went to actual data centers – but most featured liquid cooling. The University of Leeds was recognised for using British company Iceotope’s liquid cooling system for the servers in its its high performance computing (HPC) system.

Interxion won a “retrofit” award for a system that uses sea water to cool multiple data centres in Stockholm, and then uses the warm water to heat local offices before returning it to the sea. The firm says it reduced its energy needs by 80 percent and got its PUE down to 1.09.

Other winners include the US National Center For Atmospheric Research, which achieved a PUE of 1.08 in a new high-performance computing (HPC) facility, and a design innovation award went to TD Bank, which included rainwater harvesting and onsite generation in a data centre.

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