The Defense Advance Research Projects Agency (DARPA) has chosen teams from Raytheon (RTX), Draper Laboratory, and BEAM Co. to enter the first phase of the Persistent Optical Wireless Energy Relay (POWER) program. The aim of the program is to create a network of aerial nodes that can disseminate energy wirelessly to ground-based or other aerial platforms. By improving conversion efficiencies for optical energy transmissions, the program seeks to leverage power beaming to enable near-instantaneous energy transport.
Energy beaming uses the same physics as wireless communication, according to DARPA. By converting power to a propagating wave, typically electromagnetic, energy can be sent through free space, collected through an aperture, and converted back into electricity. The potential of the POWER program is to advance power beaming and create a wireless energy web that can unlock power from new and diverse sources, including space, and connect it to energy-starved consumers.
The military can benefit from wireless energy beaming by reducing the need to physically carry stored energy, such as liquid fuel, on military platforms. With a successful POWER relay, small and low-cost platforms could conduct the same missions as larger aircraft using wireless power transfer networks instead of liquid fuel. This could lead to airframes with potentially unlimited range or endurance.
Current technology allows energy to be beamed from the ground to the ground, but relaying energy between two aerial platforms is inefficient and results in energy loss. In the POWER program, the teams selected by DARPA are trying to develop an approach that keeps the energy in its original format – as optical energy – without converting it to electrical energy. The relays will benefit from transmitting at high altitudes, which is more efficient than sending energy through the lower atmosphere.
The first phase of the POWER program will last for 20 months and involve benchtop demonstrations of key technologies. The second stage will integrate relay technologies onto an existing platform for a low-power, airborne demonstration. The third stage will demonstrate the relays by sending 10 kilowatts of optical energy to a ground receiver located 200 kilometers from the ground source laser via an airborne optical pathway.
The POWER program has the potential to reshape society’s relationship with energy by enabling instant energy transport. While there are clear benefits for military applications, such as smaller and cheaper aircraft, the implications for wider society are also significant. DARPA envisions a future where a wireless energy web can unlock power from various sources and connect it to energy-starved consumers.