Data centres utilize significant amounts of copper in their electrical and data systems. Chris Sharp, the chief technology officer at data centre operator Digital Reality, stated, "I think we're at the end of copper," suggesting a shift towards reduced copper usage rather than a depletion of the metal itself. Data centres typically require around 400 tonnes of copper for a facility of approximately 100 megawatts (MW), with most of the copper allocated to electrical infrastructure and cooling systems. Up to 70 tonnes is used in computer servers, while around 20 tonnes is designated for network wiring.
Sharp indicated that the wiring connecting computer components is a target for replacement. Photonics technology, which uses light instead of electrons for data transmission, is being explored as a potential alternative. Light has been utilized for long-distance communication via optical fibre, and researchers aim to extend its application within data centres.
This technology involves intricate engineering, connecting optical components to electrical ones, sometimes directly on computer chips. Callum Littlejohns, deputy director of silicon photonics foundry Cornerstone Labs, noted that photonics could lead to significant energy savings due to reduced heat generation compared to traditional electrical systems.
Peter O'Brien, head of research for photonics packaging at Tyndall Research Institute, mentioned that while photonics technology has faced manufacturing challenges, it is now ready for widespread application. The support from companies like Nvidia has also contributed to its advancement. However, transitioning to photonics involves overcoming various engineering and cost challenges, as well as adapting existing manufacturing processes.
Andrew Wheeler, senior vice president at Hewlett Packard Labs, emphasized the need to reduce costs associated with photonics manufacturing, which is currently distributed globally. He also highlighted that while optical networking devices produce less heat, other components in data centres still generate significant heat, posing reliability concerns for optical components.
Sharp pointed out that the installation and maintenance of optical networks will require new skills for engineers and installers. Ofer Shapiro, CEO of Resolight.ai, proposed that future advancements could involve using light for both data transmission and processing, eliminating the need for constant conversion between photons and electrons.
As companies work on scaling up photonics manufacturing, Littlejohns noted the potential for reusing knowledge from electronics manufacturing to lower costs. Photonics components are generally larger than silicon components, allowing for the repurposing of older manufacturing equipment. This capability could facilitate large-scale production of photonics technology, which has the potential to support various applications.