If you’re a girl, you’ve definitely followed the sun while tanning. Always making sure your towel faced the sun in a straight angle, guaranteeing optimal sun exposure and minimal shade lines. It’s quite possible Eden Full and her girlfriends used to do this as well, and maybe this is even what led Full to invent and develop the SunSaluter. The SunSaluter is essentially a way for solar panels to gain optimal sun exposure throughout the day by moving with the sun. As a solar tracking system, the SunSaluter boosts the energy output of solar panels by 30% a day.

Full wasn’t the first to realize that sun exposure is crucial for solar panels, neither was she the first to recognize that the sun moves during the day. However, conventional solar tracking systems use intricate electronics, making them (up to 30 times) more expensive and prone to failure. Full’s desire to bring sustainable energy to underdeveloped areas required a more basic and robust approach. Enter: water. 

Water? Yes, the SunSaluter requires 4 bottles (of each 1 liter) of water. This is what happens: while the solar panel balances on a hinge, a weight hangs from the west side of the panel. On the east side, you hang a water container and a water clock. In the morning, the water container is full, pulling the panel to face east. As it empties throughout the day, it allows the panel to “follow the sun” as the balance shifts moving the panel to face west. The drip rate (which determines the rotation speed) can easily be adjusted, allowing the user to make changes as needed in different seasons for example.

And now here’s for the real humdinger: while the water allows the solar panel to gain optimal sun exposure, it is being filtered through a purifier inserted in the water container. This means that besides collecting energy, you’re actually also collecting at least 4 liters of clean water a day.

By combining these two elements, Full tackles two overwhelming statistics: 1.5 billion people lack access to electricity and 750 million people don’t have clean water. Unsurprisingly, these groups overlap quite a bit. With the SunSaluter (which costs only 3 to 4 US dollars, excl. solar panel), Full offers these communities a low-cost sustainable and easy-to-use system for producing both energy and clean water.

Back in 2011, SunSaluter won the runner-up price in the Postcode Lottery Green Challenge, allowing them to further develop and scale their product.