Solar charges today are, like most devices, getting smaller and slimmer, but also more effective. One of them definitely worth mentioning is Yolk's ultra slim (9 x 19 x 1.1 cm), light (120 grams), and on top of it also incredibly fast-charging and waterproof - Solar Paper.

In this crowdfunding campaign they are offering three models: the 5 watt, 7.5 watt and 10 watt chargers, with 2, 3 or 4 panels, respectively. On a bright, sunny day, the 5 watt charger can fully charge an iPhone 6 in about 2.5 hours (this model would cost you 120 USD), which is almost identical to charging your phone via wall charger. If you wish to charge more powerful devices like tablets or cameras, or simply require faster charging, you'll likely want to opt for one of the higher-wattage versions.

According to the manufacturer, the Solar Paper is very reliable and easy to use. While most solar chargers shut down and need to be manually reset after a cloud passes overhead and the voltage drops, Solar Paper automatically resets itself so you can keep charging, hassle free. It is also possible to expand it with magnets - if you need more power or to charge on a cloudy day, you can click new magnetic panels into place.

The first shipments of the 'green charger' will be availabe for dispatch in September 2015.