Reading: Matching Information to Paragraphs: Question 3

A Global demand for cloud storage, video streaming and, increasingly, artificial-intelligence services has pushed data-centre electricity use sharply upward. Industry estimates suggest that cooling alone can account for nearly forty percent of a typical facility's electricity, rivalling the amount spent on the computing itself.

B Engineers reasoned that a sealed capsule of servers lowered onto the seabed just offshore could use the surrounding seawater, cold and stable at depth regardless of the weather on land, to draw heat away passively, removing the need for the energy-hungry air-conditioning plants that dominate a conventional data centre's running costs.

C A prototype built from a repurposed submarine-style steel cylinder, packed with several hundred servers in a nitrogen atmosphere, was lowered onto the seabed offshore and left in place for two years, drawing power throughout via a single cable to an onshore substation, before being raised for its results to be examined.

D When opened, the capsule's servers were found to have failed at roughly one eighth the rate of an equivalent land-based batch over the same period, a difference attributed to the stable temperature, the absence of dust, and the fact that no person had opened the capsule to touch or jostle the equipment while it ran.

E Because seawater did so much of the cooling work passively, the trial used around ninety percent less electricity for temperature control than a comparable land-based facility, and at some proposed coastal sites the remaining power draw could in principle come from a nearby tidal or wave-power installation rather than the onshore grid.

F Marine biologists monitoring the site have asked how heat given off by the capsule might affect organisms living nearby, since even a small, localised rise in seabed temperature could change which species settle around the structure, and most later trials have therefore included long-term environmental monitoring as a condition of approval.

G Unlike a land-based server room, which a technician can enter at any time to fix a fault, a submerged capsule is designed to run untouched for around five years; if a fault develops earlier, operators cannot send anyone inside to repair it and must instead retrieve and replace the whole unit.

H Because well over half the world's population lives within a few hundred kilometres of a coastline, a seabed data centre near a major coastal city can shorten the distance data travels, reducing the small delay familiar from a video call or an online game between a request being sent and a reply arriving.

Which paragraph contains the following information?

Write the correct letter, A–H, for each statement.

NB You may use any letter more than once.

1. A description of why demand for computing services has been driving up electricity use in this industry.
2. An explanation of the original thinking behind placing computing equipment in the sea in the first place.
3. Details of how long an early trial ran before the equipment was brought back up for examination.
4. An explanation of how the equipment in an early trial received its electricity while it was underwater.
5. A comparison between hardware failure rates recorded underwater and those recorded on land.
6. A specific figure showing how much less electricity was needed to keep the equipment at a safe temperature.
7. A concern about the effect of heat given off by the equipment on nearby wildlife.
8. A reason why routine repairs cannot be carried out once a unit has been lowered into place.