DAPRA
The Defense Advanced Project Research Agency (DAPRA) has set a record for energy transmission with the help of a laser to a distance of 8.6 km.
It is noted that under the Persistent Optical Wireless Energy Relay (POWER) program, an 800-watt laser beam was successfully transmitted over a distance of 8.6 km. The tests were conducted in New Mexico to demonstrate the capabilities of wireless power supply for military personnel and military operations.
Within 30 seconds energy transmission the laser beam transmitted about a megajoule, demonstrating stable operation even in very dense atmospheric layers. The experiment used the POWER Receiver Array Demo (PRAD) ground-based laser system with a compact receiver equipped with a parabolic mirror. The mirror directs the laser beam to photovoltaic cells, which convert light into electrical energy again.
According to program manager Paul Jaffe, the technology has disproved the claim that it is impossible to transmission of a significant amount of energy over long distances. Already at the initial stages, the developers managed to achieve an efficiency of more than 20% in energy conversion over short distances. The main goal was to demonstrate the possibility of energy transmission over distances of more than 8 km.
The ultimate goal is to use the technology for drones that can be powered in the air In the near future, DARPA plans to move to the second phase of the program, which involves the development of vertical power transmission and the integration of a repeater system.
This power transmission system is of particular interest for military and humanitarian missions, where other methods of power transmission may not be possible. The developers also emphasize that. By directing the beams above the densest parts of the atmosphere, losses can be reduced and obstacles such as buildings, airplanes, and birds can be avoided.
The first phase of the project, divided into 3 stages, is currently underway. The developers are currently working on how to direct power in the most accurate and efficient way, changing the wavelengths of the laser beam to maintain efficiency. At the final stage, it is planned to test similar laser systems installed on aircraft and drones, which will transmit up to 10 kW of energy over distances of up to 200 km.
Source: New Atlas