This will happen. Charging your phone is a thing of the past.

Stay tuned for more.....

great. So this is community spirit.
I don't know in which state this is, but I hope that panel will somehow be more integrated (blended) in TOH, I would like to se TOH flat as it is now.

Some calculations.

-From this post I found that the phone will run for two days with everything turned off. The shortest day in Holland is 8 hours, so for two days I have 16 hours of sunlight.

The phone has a 2100mAh, 3.8V, 7.98Wh battery, which holds 28728 Joules. This amount of energy has to be restored in 16 hours. The solar-charger thus has to have at least 0.5 Watts of power.

The panel I have in mind right now has 0.935 Watts of power. This panel has to be hooked up to a voltage regulator to ensure a steady 5 volts.

With an input of 5.5 volts from the projected panel, the step-up/down dc-dc regulator has a measured efficiency of +- 93%, which leaves a comfortable .87 watts for the phone.

This is about 175ma @ 5 volts. Your regular laptop usb2.0 does 500ma, so its about 1/3rd of that.

Don't forget the power for the tracking device that will keep the solar panel constantly turned perpendicular to the sunlight.

The panel is 3mm thick, as well as the voltage regulator. So, I project the phone will we around 3mm thicker and will have slightly round back, like N9.

I would love if the other halves were stackable. Otherwise there will be constant switching, that is tiresome and I guess also wears out the mechanism that fits the halves to the back.

Solarpanel mixed with keyboard and NFC would be great .

I like the enthousiasm, but you do realise this will result in an enormous phone??

"And add a battery!" "And add a drink dispenser!"

1 step at a time.

Great project, but be careful with the panel's power rating. It is given for an incident light intensity of 1000W/m2, which is reached on a sunny day in central Europe around noon, with the panel facing the sun directly. As rule of thumby, a fixed panel installed at the optimal angle and direction gives the equivalent of 1000 full-intensity hours per year, a little bit less than 3 per day in average. It's more in summer, but less in winter, and depends strongly on the cloud conditions. So I guess your assumptions are a bit too optimistic.

To not sound that destructive: a nice addition would be an app that tells you the optimal angle based on time and GPS-location, using compas and acclerometer

Yeah, I thought about that, and I'm ok with it. I'd personally use an enormous (what is enourmous? 2cm thick?) phone most of the time, and swap the other half with a skinny one if I'm going out for drinks or something. This is where TOH is really powerful, and loads of good things could come out of it.