By concentrating sunlight on a small area, this device can hit cooking temperatures in a matter of seconds, and it requires absolutely no fuel. The SolSource solar stove is said to heat up "five times faster than a charcoal grill, deliver a whopping 1,000 watts of power, and harness sunlight seven times more efficiently than an average photovoltaic solar panel," which puts it clearly in the realm of the practical and accessible, without having a huge eco-footprint. That's something which solar chargers are still trying to achieve - sure, they're practical, and available nearly everywhere now, but they also come with a significant footprint for the materials and manufacturing.