The army has slowly taken advantage of advances in renewable energy with algae-derived jet fuel, trash-powered electricity generators, and now solar-powered aerial drones. The Air Force has spent $450,000 on a project researching the viability of dye-sensitized solar cells as a power source for unmanned aerial vehicles (UAVs). The cells, which use bacterial pigment to convert solar energy into electricity, are made out of a flexible film and thin glass coating.
When the project began at the University of Washington a few years ago, scientists experimented with dye-sensitized solar cells attached to a toy airplane. The plane couldn’t lift off the ground because the glass-based solar cells weighed it down, so university researchers replace the glass with lightweight film battery technology that allowed the plane to fly.
Dye-sensitized cells are already used to recharge cell phones, and they have many advantages over traditional silicon cells: they’re cheaper (a quarter of the cost), smaller, and can easily spread across a UAV’s wings without taking up too much space. But there’s still plenty of work to be done before the cells are mounted on Air Force UAVs. Researchers still have to test the durability of the cells, as well as whether lithium ion batteries are the best mode of energy storage for solar cell-equipped drones. If all goes well, the first solar-powered UAV will be flying in three years.