Data centres could slash power use by switching to light

Imagine a huge room filled with thousands of computers, all running at the same time. That is a data centre. Every time you watch a video online, send an email, or use a social media app, your information travels to one of these giant facilities. Data centres are essential to modern life—but they have a big problem. They use as much electricity as entire cities.

Right now, most data centres rely on copper wires to move information between computers. Copper is reliable and cheap, but it has limits. When electricity travels through copper, some of that energy turns into heat. This heat wastes power and makes cooling systems work even harder. The result? Higher bills and more environmental harm.

Technologists have spotted a smarter solution: light. Instead of sending electrical signals through metal wires, engineers are building systems that use thin strands of glass called optical fibres. Light travels through these fibres almost instantly, carrying data at incredible speeds. The technology is not brand new—scientists have studied it for decades—but only recently has it become practical and affordable enough for everyday use in data centres.

Why does light perform so much better than electricity in copper? The answer lies in physics. When electrical current moves through metal, it creates resistance. This resistance slows the signal down and generates heat as a side effect. Light, by contrast, travels through glass with almost no resistance. Almost no heat means almost no wasted energy. A data centre using optical fibres can transmit the same amount of information while drawing significantly less power from the electrical grid.

The benefits go beyond just saving energy. Light-based systems also allow data centres to process more information in the same physical space. Companies like Google and Meta have already started installing these systems in their facilities. Engineers predict that within the next five to ten years, optical fibre technology could become the standard across the industry.

Of course, switching from copper to light is not simple. Employees need training. Equipment is expensive at first. Existing wiring must be replaced carefully. But the long-term advantages are clear: lower electricity costs, reduced carbon emissions, and the ability to serve more users without building new buildings.

The shift from copper to light is one example of how innovation can solve real problems. As our world becomes more digital, data centres will only grow more important. Technologies like this help ensure that progress does not come at the cost of our planet. What aspects of technology do you think we should improve next to make the digital world more sustainable?

Inspired by reporting from BBC News.