Manufacturers Are Limiting Smartphone Capabilities. Why Smartphones Still Lack Built-in Solar Panels

Why are smartphones with built-in solar panels still missing? In modern smartphones, more than 95% of the front panel is efficiently utilized thanks to the screen. Meanwhile, the back panel is almost unused and serves no functional purpose. It could easily be replaced with a solar panel, helping users forget about dead batteries in situations when they need their phone the most. With a solar panel, the phone can always recharge itself.

At MWC 2025, we saw a phone with an integrated solar panel, but it's still just a concept. So why don’t we see commercial smartphones with built-in solar charging? After all, smartphones have become an essential part of daily life and are needed 24/7.

The Chinese company Infinix showcased several unusual concept devices at the MWC 2025 exhibition, which took place in February in Barcelona. One of them is a smartphone with built-in solar cells. These cells cover most of the back panel of the device and provide up to 2 watts of power under ideal conditions. The phone is also equipped with a Maximum Power Point Tracking (MPPT) system, which ensures optimal energy collection and prevents overheating and is a standard feature of any mature solar system.

At the same time, the solar panel does not compromise the design — Infinix Solar looks great:

Of course, a built-in solar panel won’t replace a charger or power bank, especially since smartphone batteries have a capacity of around 20 Watt*hour. But it’s a great solution for energy independence, allowing you to use your phone when you need it most. By placing a completely drained phone under bright light, it’s possible to generate enough power to “survive” until reaching a power outlet or charged powerbank.

The idea of a phone with built-in solar panels has existed almost as long as mobile phones themselves. Nokia first introduced the concept in 1997 with the Nokia 1610/1611, which had an optional removable solar battery. In 2009, Samsung released models E1107 and S7550, and LG introduced the GD510 Pop. All these phones had built-in solar elements on the back. Xiaomi patented a smartphone with an integrated solar panel in 2019.

The LG GD510 Sun Edition from 2010 could extend talk time by 2 minutes with 10 minutes of charging in bright sunlight. Samsung phones could get around 10 minutes of talk time after lying in the sun for an hour. The solar charging feature was meant to provide emergency energy only.

All of these phones came out when solar panel efficiency hovered around 20%. Today, solar panels with up to 46% efficiency are available.

Interestingly, wireless charging - recently adopted in many phones - has only about 50% efficiency. That means when charging wirelessly from a power bank, half of the powerbank's energy is lost as heat. And yet, users are expected to carry the extra weight of a power bank with them, even when it’s already discharged.

The smartphone industry is in constant pursuit of innovation — flexible displays, bezel-less screens, powerful cameras, artificial intelligence. At first glance, built-in solar panels seem like an obvious idea. But in practice, they are not used. Why?

Perhaps manufacturers aren’t truly interested in evolving smartphones in a tool that gives freedom to users. On the contrary, vendors have been narrowing smartphone functionality, removing features that were once standard — like the 3.5mm headphone jack, microSD card slot, SIM card trays. Restricting app usage on Android, limiting the region of operation and bricking the phone when user tries to change it, disabling the supported radio frequencies.

Consider the disappearance of easily replaceable removable batteries, which, fortunately, will return in 2027 due to European Union legislation. Removable batteries do not compromise water resistance — Samsung’s XCover series proves it. The Galaxy XCover 7, released in 2024, features IP68 water resistance, a removable battery, a 3.5mm headphone jack, and a microSD card slot, offering more than top flagship iPhone 16 Pro or Samsung Galaxy S25 Ultra.

Apple and Samsung don’t even introduce higher-capacity batteries, continuing to sell flagships with 4000–5000 mAh batteries while 7000 mAh batteries will become standard by the end of this year in chineese brands like Xiaomi, Oppo, Vivo.

Instead of a multifunctional, autonomous device, the modern smartphone has become a narrowly focused gadget for selling digital services. Consuming social media, streaming video and music, and other subscription-based services have become the main tasks smartphones are used for.