A quite small modern solar panel can produce 1W of power, enough to power both the Pixel Qi and the whole ARM Powered tablet motherboard behind it. Think for a second how amazing this is. They can put solar panels on the bezel and the Tablet could basically be fully solar powered, have a bigger solar panel on the back of the tablet if you want to just charge it and not use it. This compact 1W Solar panel is $3. OLPC could be using this for the upcoming OLPC XO-1.75 Laptop and the XO-3 tablet.