DARPA will use laser power beaming to power solar drones

DARPA will use the Silent Falcon UAS Technologies solar electric, fixed wing, long endurance, long range Unmanned Aircraft System (UAS) for the Stand-off Ubiquitous Power/Energy Replenishment – Power Beaming Demo (SUPER PBD).

DARPA will demonstrate the feasibility of recharging the batteries on board, in flight, by using a laser light source, allowing for indefinitely long flight times by using concatenated “Fly” and “Fly & Charge” cycles removing the need to land to refuel.

The US Navy and other areas have also been looking at power beaming with lasers and microwaves.

1. Power beaming is an emerging disruptive technology
2. There are important tradeoffs in system implementation between:
– Safety and power density
– Wavelength and aperture size
3. Recent breakthroughs in component technologies have increased system feasibility 
4. The research and industrial base is eager to develop and transition capabilities in this area to operations

16 thoughts on “DARPA will use laser power beaming to power solar drones”

  1. Note: If it’s power-beaming, it’s not “solar” (unless you count the Sun as a natural source power-beam). It will be laser or microwave or some other energy source.

  2. Note: If it’s power-beaming it’s not solar”” (unless you count the Sun as a natural source power-beam). It will be laser or microwave or some other energy source.”””

  3. I’ll note this is also applicable to all those power-point electric air taxi ideas that are currently range limited, but would be flying back and forth over much the same routes all day.

  4. One other option: mid air refueling by sending in a large, laser equipped, refueling plane.
    Though to refuel a drone it could be a fighter rather than a tanker, hence safer to send into contested airspace.

  5. Laser power beaming is of interest for electrically power drones because (a) monochromatic laser light can be band-matched to the PV material used, resulting in much higher conversion efficiencies than solar, and (b) high conversion efficiency means less waste heat per kW of delivered, and makes it feasible to use high spot intensity beams to deliver a lot of power to a small receiver.

    If the laser power is supplied from the ground, range for charging is limited to ten kilometers or so from the transmission site. The limitation isn’t from the beam itself, but from the need to have the drone within direct sight of the transmitter, at a reasonably high angle above the horizon. So while the drone needn’t land for recharging, it would need to fly back to near its base to recharge. For some applications — and especially if it’s only serving as long distance radar / lidar and communications relay — that’s no problem. It would just loiter above its base full time. For long range surveillance missions, it would be a problem.

    For operational systems, range could be extended to a thousand kilometers or more from base by deployment of an array of relay microsats in low earth orbit. Power would still originate on the ground, but would be bounced from a passing relay microsat to the drone.

  6. Note: If it’s power-beaming, it’s not “solar” (unless you count the Sun as a natural source power-beam). It will be laser or microwave or some other energy source.

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