Lightening Soldiers’ Loads by Lifting PV Cells onto Flexible Surfaces

Two thousand years ago, Roman legionnaires lugged 100-pound packs into battle. A lot has changed since then, but technology hasn’t really reduced an infantryman’s load. On the battlefield, mobility is critical—but a typical, modern Marine may shoulder an 80-pound backpack containing 20 pounds of back-up batteries for an array of electronics.

“What if we could grow solar cells on the same heavy substrate we use in the standard high-efficiency, low-cost polycrystalline processes?” asked Matthew Reese, an NREL staff scientist in PV research. Afterwards, researchers could transfer the high-efficiency cadmium telluride (CdTe) or copper indium gallium selenide cells to lighter-weight packaging—trimming the weight of the cells.

When soldiers or supply convoys are forced to move slowly on repeated trips, they can become “targets of choice” for enemy combatants. Because of this, the Energy Department and Department of Defense are looking for ways to ease such heavy burdens, and a team of researchers at the National Renewable Energy Laboratory (NREL) is exploring novel approaches for making renewable power sources lighter.

Photovoltaic (PV) cells are the military’s choice to power remote bases, but the ones it uses are not only large and inflexible, they aren’t very efficient. Last summer, NREL embarked on a $1.5 million, three-year research and development contract with the Office of Naval Research to explore making lightweight solar cells. In this work, the journey has been marked by fundamental science—and creative thinking. Read more