"reflects onto dozens of photovoltaic cells arranged around the inside of the device which convert the energy back to usable power."
This is no different that what we were considering two decades ago for the space elevator competition. One of the problems with this approach is that as the photovoltaic cells heat up their overall efficiency decreases.
bagels · 32m ago
They'll only get so hot, and you can just spread the energy across more cells, right?
jauntywundrkind · 3h ago
The application to drones seems most clear: beam drones some extra power as needed. Or continually!
I wonder how big that receiving apparatus is. Whether the receiver is gimballed, or whether the drone itself has to fly a heading to aim at the sender: TBD.
b00ty4breakfast · 2h ago
This seems very silly. It's either a death ray project in a fake mustache or somebody had earmarked a bunch of money that they had to spend before it expired.
kulahan · 2h ago
This is kinda surprising to read. I’ve never known anyone who isn’t incredibly excited at least at the prospect of wireless energy transfers. If you can do 800 watts over 8 km, surely we can do 150 watts across 3 feet in the household, and MANY of our most important discoveries come from DARPA essentially being a black budget skunkworks team.
But much of the stuff DARPA does seems weird. It’s not about ideas with solid foundation and thorough engineering, it’s about crapshoots that might work and would pay off in some way - often any financially feasible way.
They once put “cats” on guns in hopes it would surprise opponents even just for a quarter second, giving your spec ops dudes the advantage. They tried to create angled guns that could shoot around corners like 20 years ago. All kinds of crazy stuff! It would be a lot of fun to work there, I think.
No comments yet
janalsncm · 3h ago
Could this also be a viable alternative to HVDC lines for civilian applications?
theamk · 3h ago
No. 800 watts (vs megawatts for HVDC). 5 miles vs thousands of miles. 20% efficiency optical to electrical - so electrical vs electrical is much worse - vs 90%+.
This is so much worse in every aspect it's not really compareable.
other_herbert · 3h ago
The key thing they aren't saying is how much power it took to "send" 800 watts 5.3 miles...
bracketfocus · 3h ago
They mentioned that it was 20% efficient at a closer distance.
So likely much lower than that.
throwaway81523 · 2h ago
Wow that's a long way from the proposals for sending GW of microwave power from satellites.
pfdietz · 1h ago
Laser power beaming from space could be useful at lower power levels than that, for example for powering aircraft.
This is no different that what we were considering two decades ago for the space elevator competition. One of the problems with this approach is that as the photovoltaic cells heat up their overall efficiency decreases.
I wonder how big that receiving apparatus is. Whether the receiver is gimballed, or whether the drone itself has to fly a heading to aim at the sender: TBD.
But much of the stuff DARPA does seems weird. It’s not about ideas with solid foundation and thorough engineering, it’s about crapshoots that might work and would pay off in some way - often any financially feasible way.
They once put “cats” on guns in hopes it would surprise opponents even just for a quarter second, giving your spec ops dudes the advantage. They tried to create angled guns that could shoot around corners like 20 years ago. All kinds of crazy stuff! It would be a lot of fun to work there, I think.
No comments yet
This is so much worse in every aspect it's not really compareable.
So likely much lower than that.