The Rock Out 2 portable speaker by Goal Zero, a pioneer in mobile solar technology, has a photovoltaic panel on the back that is designed to power the device without the use of electricity (though it is equipped with a built-in USB jack for a quick charge from the grid). It is housed in a weatherproof shell designed to protect it from the elements. Suggested retail price: $129.99. Photo courtesy of Goal Zero. Photo 6 of 7 in Innovations from the 2014 International CES Part One by William Lamb

Innovations from the 2014 International CES Part One

6 of 7

The Rock Out 2 portable speaker by Goal Zero, a pioneer in mobile solar technology, has a photovoltaic panel on the back that is designed to power the device without the use of electricity (though it is equipped with a built-in USB jack for a quick charge from the grid). It is housed in a weatherproof shell designed to protect it from the elements. Suggested retail price: $129.99. Photo courtesy of Goal Zero.