In collaboration with Ilya Kazansky, CEO, SPhotonix
In 2024, the world produced 149 zettabytes of data. That number is hard to picture until someone explains that 90 per cent of all digital information has been created in just the past two years. Artificial intelligence systems train on it. Governments archive it. Hospitals depend on it. And quietly, server farms hum day and night to hold it all in place.
The demand shows no sign of easing. Projections suggest global data volumes could surpass 394 zettabytes within two years. Disk-based data centre capacity is expected to experience annual growth rates of between 19 and 22 percent through the end of the decade. Expansion feels inevitable.
So does the strain.
Data centres already consume around 460 terawatt-hours of electricity each year. Analysts expect that to exceed 1,000 terawatt-hours. By 2030, emissions from the industry could reach 2.5 billion tonnes of carbon dioxide. I remember visiting a data centre on a grey industrial estate a few years ago; the building looked anonymous, but the cooling systems roared like aircraft engines.
Most long-term archives rely on hard disk drives or magnetic tape. Both degrade. Both require tightly controlled temperature and humidity. Every decade or so, data must be migrated to new hardware before the old media fails. It’s a ritual of copying and replacing, repeating across thousands of facilities.
The process creates waste. In 2023, the world generated 53.6 million metric tonnes of electronic waste. Storage devices are particularly awkward to recycle, layered with rare metals and synthetic materials. Much of it ends up stockpiled or exported, rarely discussed when companies speak about digital transformation.
Long-term archival storage carries a quiet anxiety: the fear that something will be lost in transition. A corrupted backup. A degraded tape. A forgotten migration schedule. Industries such as healthcare, finance, and legal services cannot afford that risk; their records must endure decades, sometimes indefinitely.
Against that backdrop, a small cluster of researchers has been refining something that sounds almost improbable: storing data in glass.
Using femtosecond lasers, engineers can write nanostructures inside silica glass, encoding information in multiple dimensions. The approach is sometimes called 5D optical storage. Instead of magnetism or electrical charge, it relies on microscopic structural changes within the material itself. The data, once written, requires no power to persist.
SPhotonix, drawing on more than three decades of research led by Professor Peter Kazansky at the University of Southampton, has demonstrated a five-inch glass platter capable of storing up to 360 terabytes. The company calls it a 5D Memory Crystal™. The claim is that the data etched inside could remain stable for billions of years, immune to heat, water, electromagnetic pulses.
I found myself pausing at that figure — billions of years — and wondering who, exactly, we imagine will be reading it.
There are practical motivations beyond longevity. Optical glass storage does not require continuous cooling or electricity once written. For organisations wrestling with compliance obligations and sustainability targets, that matters. New regulations, such as stricter energy efficiency standards across Europe, are pushing data centres to lower their power usage effectiveness. Achieving those targets with spinning disks alone will be challenging.
Cost enters the conversation too. Traditional archival storage involves ongoing operational expenses: energy, maintenance, hardware refresh cycles, and migration programmes. With glass, much of that recurring burden disappears after the initial write. Data can be stored offline, physically shelved rather than electrically sustained.
Of course, optical glass is not a replacement for the cloud services people use every day. It is “cold storage” in the truest sense. Retrieval is slower. Writing is deliberate. But long-term archives rarely demand instant access; they demand certainty.
There was a moment in a recent demonstration where researchers showed the entire human genome encoded within a small piece of glass. It looked unremarkable, almost like a paperweight. That ordinariness felt significant. The future of archival data may not be a louder machine or a bigger building, but something quieter.
Glass does not spin. It does not hum.
It simply holds.
