Nearly-transparent screen adds solar charge to phones “Don't let the perfect be the enemy of the good” seems to be the motto of a French startup that believes it has a good-enough approach to adding solar charging to smartphones. Rather than wait until fully-transparent solar cells are ready for prime time, SunPartner is using standard thin-film solar cells in an arrangement …
They should face the solar cells inwards instead of outwards - that way, whenever the screen is turned on, the phone would self-charge from the light generated by the screen!
But on a more serious note (and assuming that solar cells of this size can actually generate enough charge to be useful) - why not put solar cells on the back of the phone instead of over the screen? I could certainly learn to live with keeping my phone face-down on my desk rather than face up, if that is all it takes to avoid needing to charge it!
I would think the amount of power generated indoors is too little to even power a notification led, which means it would make no difference if you keep it screen up or screen down on a desk. Unless your desk is outdoors, that is.
Also makes me wonder why you'd point the screen at the sun, will just make the screen contents invisible and fingerprints+scratches very visible..
Be worth testing cells on the phone casing but I'd guess the normal holding position, screen facing the main light source (the sky/house lights) and hand blocking the back would render it useless for too much time for most users. As a 2nd screen device it needs to face up for maximum convenience anyway.
A more subtle issue is physically protecting the cells. That comes free embedded in the screen but adds weight and bulk anywhere else.
TBH I can't see much point for this low a power contribution, especially with new Lithium/Sulphur battery tech on its way and more effective external solar chargers available where there's a real need.
I'm pretty sure there's other models out there which work with every phone including Apple's, too.
an automatic watch movement powering a generator? No light or any exposure needed, just the bunny for people who leave their phone in their pocket . . .
I'm actually only partly joking here, I find. When you're stationary, the phone can be on a charger; it can't be if you're moving about.
Hm.
I was thinking the same, a kinetic charger seems more suited to a device that's usually being bounced around in dark pockets, I suspect the problems with that idea are a) insignificant unless user is sat on a washing machine during spin cycle, b) mechanical wear and tear and c) shifting balance point in an expensive fragile device that's designed to be lightly cradled in the hand during use. I suppose the charging motion looking like a wanking gesture won't be a big sales point either.
When Apple released the original iPhone running Unix with limited CPU, RAM and disk I hoped that we might see a resurgence in efficient optimised code but sadly we decided to fuck all that and throw Ghz, cores and ram at the problem instead, rendering these ambient charging efforts as little more than gimmicks
That will fit nicely with the idea of the solar bit facing inwards - only battery life stops some from gabbling.
Maybe also use the output from accelerometers etc. to harness the power from those who wear an earpiece and wave the mobe around.
Near-field charging to steal leccy from other commuters?
Or, for the 'green' phone -- Ley-line charging.
Except for the few brief minutes per use, mine's either in my pocket, or in the charging station. It doesn't see much daylight, not even close to enough to top off a charge.
Now a portable charging station, with a separate solar panel that could be placed in a window, that might be useful.
It doesn't necessarily have to be sunlight. It wouldn't charge as much under artificial light, given that isn't as strong as the sun, so I'm not sure if it is worth it. I wonder how much of a charge it could pick up sitting under typical office lighting all day?
The reason this is a big "who gives a ...?" to me is that I keep my phone in my pocket. I really don't want to be leaving it lying about to pick up a charge. Nightly charging is fine for me.
Why not install small thermocouples inside the case instead?
Given the amount of heat generated by the CPU as the phone operates, this would provide a more constant stream of micro-trickle charging than solar cells over the screen.
< Beer, cos i deserve one after all that hard thunking.
Why would I spend hundreds of quid on a device that is entirely defined by the quality of its screen, just to lose 18% of its quality? 20% improvement in battery life isn't a game-changer. It's the difference between charging the phone every night and charging the phone every night. They're going to have to go a lot better than 90% transparency to get people on board.
Currently 82% transparent. So 18% of the power it generates is used by the 18% increase in screen brightness required to overcome the opacity? And then a query over how effective this charger could be in the light conditions a phone is generally used in.
Sounds improbable on first inspection. Need to some fact and figures to back up the claims.
Problem again is that given how frugal those things are for power anyway, it's not exactly worthwhile there either.
The missus uses her Kindle day in and day out, and it only ends up on her laptop's USB port for charging every 2-3 weeks or so at most (usually more like monthly).
And again most of the time it'd be used in conditions where solar charging isn't really an option anyway, as the one thing those things suffer from somewhat is viewing in direct sunlight...
Teh fizzicks of an LED display, if I remember rightly, is the same as that of a standard photovoltaic cells:
Electron on high-voltage side of junction <-> photon + low-voltage electron.
Therefore if your phone has an LED display it should be able to push a trickly charge-voltage with only minimal rewiring behind the scenes. In fact this is an occasionally-used test procedure for PV cells, to run them backwards and see what comes out.
It has been bothering me for a while that I can't harvest power from my LED telly when it is turned off, multiple square metres of perfectly good PV cell should be in use, even if it is only enough to drive the standy mode, that is better than nothing! Can anyone explain why this is not already a reality?
The reason why it doesn't work is that in front of your LED panel is your actual LCD panel, which, powered down, is blocking the light to the LEDs.
'LED' screens are misnamed. They are LED-backlit LCD screens. There are real LED screens, but they are not for your average home TV but multi-square-yard advertising panels (Picadilly Circus and the likes) and scoreboards in stadiums.
Even so, if you could make your LCD-panel default to transparent when it's off, you'd still face the problem that the polarising filter is in the way, cutting 50% of the ambient light out, the light not hitting at right angles, the LCD panel being in the way and LEDs not optimised for 'reverse opration'. All in all, while it could potentially produce some electricity, it'd be way too inefficient to contemplate. Think about, as a guesstimate, an Eta of <1% for the whole circuit.
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