Sunshine might seem like a rare luxury at this time of year, but solar rays still punctuate grey February skylines.
You don’t need to be underneath a Caribbean sunrise for each new day to herald hours of valuable solar energy.
Even on a gloomy winter’s morning, electrical charge is being accumulated by photovoltaic cells on rooftops up and down the land, as solar panels convert the sun’s rays into electricity.
After all, our homes have a constant demand for power. And so do our indispensable smartphones and tablets.
As a consequence, scientists are now investigating whether solar powered smartphones might represent a match made in heaven (or in outer space).
The light fantastic
Breakthroughs in solar powered smartphones are being led by the same experts responsible for transmitting broadband data through light emitting diodes.
Distributing digital data across the visible light spectrum instead of the radio frequency spectrum offers exciting potential for always-on, ultra-fast and interference-free broadband.
However, it requires mobile devices to be fitted with photodiode sensors, capable of detecting individual light photons distributed from a binary light source – typically an LED bulb.
It’s not a huge evolutionary leap to fit photovoltaic sensors as well – especially if the device’s outer shell becomes one big PV surface.
Samsung and Apple have been experimenting with solar powered smartphones since the Noughties.
It’s a full ten years since Samsung launched the UK’s first solar phone – the Blue Earth.
This eco-friendly device was way ahead of its time. Disastrous sales figures saw it rapidly dropped from Samsung’s handset range, and few consumers remember it.
Ray of light
Smartphones have increased in size since 2009, creating much bigger surface areas for hosting PV cells.
Solar panels themselves have also evolved. In 2009, they delivered around 17 per cent efficiency, whereas modern cells are approaching 45 per cent efficiency.
That’s the difference between being able to maintain a device’s battery life while it’s on standby, and maintaining charge while a phone call takes place.
Further evidence of progress is demonstrated by changes occurring across the domestic solar energy sector.
The cost of installing solar panels onto rooftops has dropped by more than 60 per cent since 2008, as hardware becomes cheaper to produce and install.
These economies of scale are filtering down into smaller-scale applications, raising hopes of a solar powered smartphone revolution.
Keeping up appearances
In recent years, there has been a growing focus on transparent photovoltaic panels and invisible molecular coatings, rather than those traditional blue panels.
This would enable device manufacturers to continue producing attractive handsets whose aesthetics mimic today’s glassy and metallic devices.
Technological advances are still needed before solar powered smartphones will be able to function without any mains-powered charging.
Nonetheless, it’s hoped tomorrow’s smartphones will derive at least part of their energy needs from natural daylight – even if the sun isn’t shining…