Where do old smartphones end up?

Researchers at the University of Tartu Institute of Computer Science are proposing an unexpected way to combat electronic waste: recycling obsolete phones into low-power servers capable of storing and processing data. Creating such a system costs only about €8 per device.

TechXplore writes about it.

How are old phones used to create data centers?

Every year, more than 1.2 billion smartphones are produced worldwide. The production of each gadget requires significant energy resources and natural materials and is accompanied by carbon dioxide emissions. Despite this, users replace their phones, which are still in good working order, on average every 2-3 years. The best solution would be to rethink our consumption habits, but rapid progress makes previous models obsolete, so alternative approaches are needed.

Huber Flores, Ulrich Norbisrath, Zhigang Yin, and Perseverance Ngoy, together with international colleagues, described their solution in the journal IEEE Pervasive Computing.

"Innovation often begins not with something new, but with a new way of thinking about the old, re-imagining its role in shaping the future," Flores explained.

Researchers have shown that by connecting several old smartphones, it is possible to create a fully functional, albeit tiny, data center.

In the first stage, the batteries were removed from the phones, and an external power supply was connected to prevent possible chemical leakage. Four devices were placed in 3D-printed cases and combined into a single unit. The prototype was tested underwater: the system automatically counted marine species, performing the work that is usually done by a diver with a camera.

In urban areas, such "servers in a box" could be installed, for example, at public transport stops. The phones would collect real-time data on passenger traffic, helping to optimize routes and timetables.

The results of the research confirm that even outdated technology can be useful if its role is rethought.

"Sustainability is not just about preserving the future—it's about reimagining the present, where yesterday's devices become tomorrow's opportunities," Norbisrath added.

By turning unwanted smartphones into energy-efficient data centers, we reduce waste and take a step towards a more environmentally friendly digital infrastructure.

As a reminder, sometimes there is a need to reduce dependence on smartphones without completely abandoning technology. In such cases, push-button phones can be a good solution.

We also wrote that overheating a smartphone not only reduces its performance but also accelerates battery wear and can damage the electronics. In critical cases, it can even lead to a fire, so it is important to follow the simple rules of use.