Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Power The Military

Researchers Transmit Energy With A Laser In 'Historic' Power-Beaming Demonstration (navy.mil) 109

Posted by EditorDavid from the remotely-powered dept.
"First the first time, hundreds of watts of power were wirelessly transmitted hundreds of meters [video], with an integrated system that ensured the safety of operators and bystanders," writes an anonymous Slashdot reader -- sharing a new press release from the U.S. Naval Research Lab. "This could be the first step towards drones that never have to land..."

According to the Navy, the power transmitted came from "an electrical outlet in the building": On one end of the of the testing facility -- one of the largest test facilities for model ships in the world -- the receiver was converting the laser energy to DC power, which an inverter was turning into AC power to run lights, several laptops, and a coffeemaker that the organizers were using to make coffee for the attendees, or 'laser lattes'...

At NRL, Paul Jaffe, an electronics engineer with the U.S. Naval Research Laboratory has been conducting space-based solar energy research for more than a decade... According to Jaffe, power beaming could also make possible the transmission of power from solar-energy-collecting satellites in space to the ground, wherever it's needed... Imagine using it to send power to locations that are remote, hard to reach or lack infrastructure, he suggested.
This discussion has been archived. No new comments can be posted.

Researchers Transmit Energy With A Laser In 'Historic' Power-Beaming Demonstration More

Researchers Transmit Energy With A Laser In 'Historic' Power-Beaming Demonstration

Comments Filter:

  • Losses, anyone? Efficiency numbers? (Score:3)

    by weilawei ( 897823 ) on Saturday October 26, 2019 @09:00PM (#59351260)

    It was a long-range, free-space power beaming system - the first of its kind. Attendees that day, May 23, could see the system itself—the two 13-foot-high towers, one a 2-kilowatt laser transmitter, the other a receiver of specially designed photovoltaics. But the important part, the laser that was beaming 400 watts of power across 325 meters, from the transmitter to the receiver, was invisible to the naked eye.

    Ah yes a 2kw laser to move 400 watts. That's highly efficient and safe. /s

    • Re:Losses, anyone? Efficiency numbers? (Score:5, Insightful)

      by weilawei ( 897823 ) on Saturday October 26, 2019 @09:01PM (#59351266)

      Just to be clear, I actually think the impressive bit is the receiver not getting immediately melted into uselessness.

      • If you remember these Lightcraft [youtu.be] vehicles/projectiles from years ago they did work by tuning the received laser light straight into heat, being propelled by the expanding air. Pretty cool.

        You can sort of imagine a a ground-laser-powered UAV that uses onboard steam turbines to turn propellers. The energy receiver would just need to be hot enough to boil recirculating water.

        • If you remember these Lyrics [youtu.be] by Queen from years ago, you will keep asking yourself how we do not have this much more deadly combination than sharks with lazer beams.

    • Re: (Score:2)

      by Eloking ( 877834 )

      It was a long-range, free-space power beaming system - the first of its kind. Attendees that day, May 23, could see the system itself—the two 13-foot-high towers, one a 2-kilowatt laser transmitter, the other a receiver of specially designed photovoltaics. But the important part, the laser that was beaming 400 watts of power across 325 meters, from the transmitter to the receiver, was invisible to the naked eye.

      Ah yes a 2kw laser to move 400 watts. That's highly efficient and safe. /s

      Even with 80% losses, it will be useful.

      I agree that efficiency is key, but we don't have much. How the range affect the efficiency? Will cloud, wind etc. affect it as well?

      • This would be useful where energy creation can be made in abundance but transporting it is extremely costly or technically infeasible to the point that the net efficiency is even lower that beaming the energy. Such as future moon based reactors or energy mining operations, etc. Similarly, beaming energy to receivers on space vessels or probes could also be useful.

        • Re: (Score:3)

          by hazem ( 472289 )

          This would be useful where energy creation can be made in abundance but transporting it is extremely costly or technically infeasible to the point that the net efficiency is even lower that beaming the energy.

          This reminds me of Asimov's short story, Reason, where they have large solar collectors near the orbit of Mercury, then beam/direct concentrated energy back to receiving stations on earth. "Cheapest energy in the solar system". If the energy source is abundant, then even losing a lot of it in transmission could be a benefit.

          https://en.wikipedia.org/wiki/... [wikipedia.org]

          • Reminds me of Larry Niven talking of microwave lasers in orbit beaming power back to a collector in a Nevada desert (with a large fence around it with signs saying "cross this line and you will be cooked") and still thinking that the environmentalists would go to blow it up because "bad tech".

            I suppose it all comes down to cost - the cost of putting solar panels in space is huge, and the maintenanc eof them is huge, and the cost of the laser/collector system is huge and the power gained... is relatively tin

        • Re: (Score:3)

          by Dunbal ( 464142 ) *

          moon based reactors or energy mining operations

          You plan on striking oil on the moon, are you?

      • "Even with 80% losses, it will be useful."

        Yes, you can illuminate Taliban caves in Afghanistan and they don't even need lightbulbs for that.

    • They should just use Tesla coils, a properly tuned one breaks 90% efficiency over larger distances.

      • Re: (Score:3)

        by Ozoner ( 1406169 )

        The laws of physics say "utter rubbish" to this.

        Once outside the Near-Field zone, magnetic transfer doesn't work, and the range of Eletromagnetic transfer is limited by the Inverse-D-Squared law.

        There is no such thing as a free lunch

        • Whenever I see mention this, I'm always reminded of the 2009 CCC presentation https://media.ccc.de/v/26c3-36... [media.ccc.de] . Supposedly there's a trick to it involving resonance, and that the math checks out.

          Interestingly, I did a youtube search for 'tesla wireless power transfer', and there's a lot more videos on it now.

          • Re: (Score:2)

            by Ozoner ( 1406169 )

            > Supposedly there's a trick to it involving resonance,

            There is no magic in Resonant Power Transfer.
            It is still limited by the Inverse-Square Law.
            eg is inefficient and limited to very short range.

            Maxwell did the maths a long time ago.

            • Assuming short range, having dual tuned resonant frequencies buys you a lot of efficiency.

              Faraday and Ampere did the math, Maxwell unified and republished the equations so that they were using the same terms. But you only need Faraday's Law and Ampere's Law to calculate this.

              Nobody did the math to find out the implications of using tuned resonant frequencies for a long time after that.

          • Resonant inductive power transfer is what a wireless electric toothbrush uses so that there is no exposed metal in the connection between the charging base and the toothbrush.

            The distance you're limited to if you want to keep efficiency high is approximately the width of your coil. So a wireless cell phone charger pad with a 4" coil can a good connection for nearly 4", but only if the cell phone also has a 4" coil and if they're lined up perfectly. With a 2" coil in the cell phone, and the resulting imperfe

        • "There is no such thing as a free lunch"

          But there's something called 'all-you-can-eat-buffet', which is almost as good.

        • There is no such thing as a free lunch

          This is either a Red Herring or a Straw Man, or maybe both. I'm not sure.

          Nobody is ever claiming there is a free lunch. The arguments are about where the bill gets sent.

          Not everybody has calculated how much credit their coil has, so they make wrong guesses about the coupling distance, but it isn't because they thought that lunch was free.

      • Re: (Score:2)

        by rtb61 ( 674572 )

        They should just generate the energy where they need it. This kind of technology was flash decades ago and they it was about using microwave but as it developed so energy generating systems developed and they are simply easier and more efficient.

        So for example you fitted a radar system to a drone, you can use microwaves to power the drone and get it to hover and 15,000m for better over the horizon, or is it just simpler to tweak the design and a hydrogen balloon around the perimeter to help drop weight and

        • So for example you fitted a radar system to a drone, you can use microwaves to power the drone and get it to hover and 15,000m for better over the horizon, or is it just simpler to tweak the design and a hydrogen balloon around the perimeter to help drop weight and simply have more than one, and use them on rotation

          You don't understand the applications and the realities they impose.

          In your story, the end of the rotation happens when the drone gets shot down by small arms because it has to operate far below 15km.

          And in no way does it even address the orbit->ground scenario.

          So you address none of the use cases that are made possible by this technology, and only suppose that if you're using use cases that work with the old technology, you can keep using the old technology. Duh.

      • They should just use Tesla coils, a properly tuned one breaks 90% efficiency over larger distances.

        You're confusing a Tesla Coil with Tesla's idea to additionally ionize the atmosphere to use it as a giant capacitor for regional area power distribution.

        Wires are better for that, though. Wireless power transfer isn't that beneficial for area transmission because it is inefficient. The useful applications are point to point where wires are impractical, such orbit to ground, or ground to drone.

        In the phrase "breaks 90% efficiency over larger distances" they meant "larger distances than you use inside a norm

    • Re: (Score:2)

      by Ozan ( 176854 )
      Are you expecting military operations to regard efficiency in their choice of methods?
    • For applications where weight is important (aircraft), this sort of efficiency is fine. You end up saving significantly on vehicle weight / required vehicle energy when you do not have to carry fuel. I could see a system where a vehicle is given sufficient internal energy to reach a desired altitude at which point it could switch over to the free-space beaming system. To save additional weight, the battery could be jettisoned once the desired altitude is reached.

      • Re: (Score:2)

        by Dunbal ( 464142 ) *
        Now having to carry fuel vs having to stay within line of sight of your laser device. Hmmmm.
        • At least continental flights could take advantage of this just fine.

          • Re: (Score:2)

            by Dunbal ( 464142 ) *
            Until it gets cloudy and the plane plummets out of the sky. Lasers don't do so well through clouds.
            • Might depend on the wavelength, the presence of auxiliary batteries on the plane to cover for interrruptions, flight altitude, etc. Of course there's some issues to be solved as well.

      • You can go further. Launch the drones from a plane, with ordnance or surveillance payload, and have satellites beam energy to them for months worth of flight. You wouldn't need any ground crew nearby and can react to events within minutes rather than hours. It can take days to eventually get home for routine maintenance.

        You could have satellites without panels or power equipment weight that get their energy from other "generator" satellites.

        There are tons of military applications.

    • Yes, it's totally inefficient. And unsurprisingly, what are they marketing this towards? Military applications...

    • First the first time, correct grammar is transmitted over the internet through a slashdot article.

    • The laser was most likely pulsed.
      And then again a 'solar cell' is not 100% efficient.

      Bottom line the question is what you want to achieve, if you want to have a drone 200days over your head >50% might be acceptable for you.

    • Re: (Score:2)

      by ceoyoyo ( 59147 )

      Presumably the 2 kw is laser output power too, which means that the actual electrical input would have been considerably more than that.

  • The real question is, can it be attached to a shark?

    • The real question is, can it be attached to a shark?

      Call me when it can it be used to transmit a shark between two 13-foot tall towers, 325 meters apart --- hopefully w/o an 80% loss.

  • They say the rig ensures the "safety of operators and bystanders" but 400 Watt lasers will instantly burn all kinds of things. Even if it does not burn your retina for visible light, that's a tremendous amount of energy in a beam. It is lower energy than many industrial cutting lasers, but even some shiny dust could reflect enough energy to destroy camera sensors and cause other harm. "Does not impair human sight" doesn't equate with "safe".

    • Here's the thing. That's 400W of usable power after everything is said and done.

      Its 2000 watts that's going to try and dissipate itself in your flesh.

    • Re: (Score:2)

      by ceoyoyo ( 59147 )

      but 400 Watt lasers will instantly burn all kinds of things.

      You're making assumptions based on insufficient information. To determine the danger of a laser you need to know the power and how much area that power is spread over.

      To make these things safe the usual approach is to either (1) spread the beam over a sufficient area so it's not dangerous or can be cut off quickly enough to not be dangerous or (2) surround a potentially dangerous beam with a low intensity beam and sensors that can cut off the main

  • 2 kw transmitter and 400 watts being beamed. Does that mean there is a 400/2000 = 20% transmission efficiency over 325 meters?

    • It depends. Is 2KW the output power of the laser, or is that the power fed in to it, in order to get 400W a few hundred metres away?

      As for powering a drone that would never have to land? Only it that drone stays below the clouds and never strays far from its transmitter.

    • Re: (Score:2)

      by ceoyoyo ( 59147 )

      Unlikely. Lasers are usually rated by output power, so the efficiency you calculate is too high.

  • beaming power through a redshirt https://www.youtube.com/watch?... [youtube.com]

  • Seems a typical covfefe maker [mrcoffee.com] uses about 900 watts. Laptop brick I've got lying on my desk says it uses 1.2A at 120VAC, so that's 144 watts. Then there's the lights...

    Yup, this is starting to look like myth busted... There's probably batteries hidden inside that box.

  • With great power comes great responsibility.

  • Reminds me of an old Umgah joke... (Score:5, Funny)

    by mishehu ( 712452 ) on Saturday October 26, 2019 @10:48PM (#59351432)

    Q: What do you get when you combine deuterium pellet terawatt laser with ancient earth leader from the asian steppes?

    A: Khanfusion!

  • I have to ask... (Score:5, Funny)

    by Blinkin1200 ( 917437 ) on Saturday October 26, 2019 @10:58PM (#59351450)

    What happens if you cross the beams? Would that be a bad thing?

  • Other good stuff from NRL (Score:5, Interesting)

    by blindseer ( 891256 ) <blindseer@noSPAm.earthlink.net> on Saturday October 26, 2019 @11:38PM (#59351510)

    Why isn't this technology from NRL getting more attention?
    This is a 2 minute video, from the same NRL YouTube channel as the one featured, showing a technology that can produce liquid fuels from seawater and electricity. https://www.youtube.com/watch?... [youtube.com]

    Here's a 30 minute video with more detail: https://www.youtube.com/watch?... [youtube.com]

    Possibly a better video giving a nice overview of the program in under 15 minutes: https://www.youtube.com/watch?... [youtube.com]

    A nuclear powered aircraft carrier could potentially produce fuel for the aircraft it carries at sea. If there is a large enough production of fuel then it can also fuel the flotilla of ships that surround and protect it. A more likely outcome is a few other ships being nuclear powered and producing fuel.

    This technology has direct civil application by use of a nuclear power plant producing carbon neutral fuel for planes, train, and automobiles. The last time I brought this up some knucklehead replied with, "I can't run my car on jet fuel you idiot!" First, the process can produce any hydrocarbon, the Navy is simply most interested in producing the JP-5 they use for everything from jet planes and helicopters to trucks and field stoves. Producing methane, propane, octane, or cetane, is all the same process but a matter of how long it "cooks". Second, you can burn jet fuel in your car, because jet fuel is kerosene. Kerosene burns just fine in a diesel engine and reasonably well in a gasoline engine, perhaps with some adjustment or additives.

    Beaming energy to an airborne drone seems reasonable, but then so does a process that can produce a liquid fuel to refuel such things that can run off a nuclear reactor on a ship, or solar panels on some forward operating base. The Navy should already be familiar with air to air refueling. Beaming energy from space is not likely to ever be feasible, just ask Elon Musk what he thinks about that. To beam the energy means having something to produce this energy, like a nuclear reactor or solar panels, or having an energy dense store of energy to draw from, like a tank of fuel. In such cases why not just move the fuel?

    One more thing to consider, why is it that the best ideas for energy production, transmission, and storage are coming from the Department of Defense? What is the Department of Energy doing? One guess is that they are pissing away money on ITER and other fusion projects that have no possibility to reach commercial use for decades.

    • Re: (Score:2)

      by Dunbal ( 464142 ) *
      100 mililitres per day. How many planes do you plan on fueling with that? You would need to scale it up several tens of thousands of times.
    • The Navy can afford expensive fuel because their fuel is *already* expensive. But people on land are not going to be interested in your fuel that is vastly more expensive what they're buying right now, especially when their alternative is to purchase several times cheaper surplus electric generation.

      • The Navy can afford expensive fuel because their fuel is *already* expensive. But people on land are not going to be interested in your fuel that is vastly more expensive what they're buying right now, especially when their alternative is to purchase several times cheaper surplus electric generation.

        The people running these prototype fuel plants claim $4/gallon fuel now, less than half the average after tax price of fuel in the USA. Do you expect that petroleum fuel prices will never rise? That nothing would disrupt the imports of the raw materials needed for electric vehicles? Did you consider that there are no electric aircraft offering passenger service yet?

        This is a technology that is being produced at a price that is than double what is paid now for a fuel that is blamed for 1/3rd of the CO2 em

        • Even switching to synthetic fuel is not likely to solve air quality issues in cities, for example. Yes, the fuel is often way cleaner, but combustion still has issues. So you're just replacing the fuel source while not avoiding all externalities.

          If they're claiming $4/gallon now, why aren't they already making a killing here in Europe? Car owners would tear these people's arms off!

          • Even switching to synthetic fuel is not likely to solve air quality issues in cities, for example. Yes, the fuel is often way cleaner, but combustion still has issues. So you're just replacing the fuel source while not avoiding all externalities.

            I see, because it's not a perfect solution therefore it's worthless. Again, this is a fuel that can make every plane, train, and automobile carbon neutral overnight and you consider this something not worth developing because it might put a little NOx in the air, something that's already a non-issue with all new vehicles.

            If they're claiming $4/gallon now, why aren't they already making a killing here in Europe? Car owners would tear these people's arms off!

            Probably because they thought like you did, because it can't solve every problem therefore they can't be bothered to even consider it.

            I swear, people like yourself are going to get us all

          • And the synth fuel is burned with 20% efficiency ...

    • A nuclear powered aircraft carrier could potentially produce fuel for the aircraft it carries at sea.

      The new Ford class Aircraft Carrier can put out roughly 250 megawatts of electrical power. Your link seems to suggest that this technology can produce 1.5L of fuel per kilowatt per day. That means if you were to use half of the electrical output of both nuclear plants for fuel production, you could produce about 83,000L per day. That seems like a lot, but keep in mind the F-18 carries almost 5,000 L in it's internal tanks alone, and each carrier will have about 11 MILLION litres of jet fuel when it leave

      • Realistically you probably wouldn't even be able to produce 83K on a regular basis, but even if you could it's not going to be enough to supply your planes even during routine ops, let alone during wartime. It might still be useful, but not to the extent you're imagining.

        Putting this technology on current carriers would be mostly a proof of concept and/or a means of producing something in dire conditions. Next generation carriers could have this technology integrated into it, and the nuclear power plant sized accordingly.

        There is also the possibility of a ship built for the specific purpose of producing fuel for a carrier group. It can be part of the flotilla going from ship to ship constantly topping off their tanks. The ship can serve other purposes as well, depending

        • Putting this technology on current carriers would be mostly a proof of concept and/or a means of producing something in dire conditions. Next generation carriers could have this technology integrated into it, and the nuclear power plant sized accordingly.

          Yes, this would make it feasible and it probably should be explored for future designs. But that would put actual deployment 30+ years into the future.

          If there's a "carbon tax" imposed on petroleum fuels then this carbon neutral process should be exempt and that would change the economics as well.

          You would need a carbon tax to ever bring the price down to parity. I'm ok with that, but not if it means that all of our fuel costs suddenly triple.

          If the price of these manufactured fuels can be further reduced (perhaps partly by more efficient hydrolysis as you suggested, and partly by a continued drop in the cost of solar/wind/nuclear) then bringing in

      • A nuclear powered aircraft carrier could potentially produce fuel for the aircraft it carries at sea.

        The new Ford class Aircraft Carrier can put out roughly 250 megawatts of electrical power. Your link seems to suggest that this technology can produce 1.5L of fuel per kilowatt per day. That means if you were to use half of the electrical output of both nuclear plants for fuel production, you could produce about 83,000L per day. That seems like a lot, but keep in mind the F-18 carries almost 5,000 L in it's internal tanks alone, and each carrier will have about 11 MILLION litres of jet fuel when it leaves port.

        Realistically you probably wouldn't even be able to produce 83K on a regular basis, but even if you could it's not going to be enough to supply your planes even during routine ops, let alone during wartime. It might still be useful, but not to the extent you're imagining.

        An aircraft carrier not designed to produce its own aircraft fuel won't be able to. You can't just bolt this sort of thing on to an existing design. But your calculation actually shows feasibility, not infeasibility. The production you describe replaces the entire jet fuel load in 130 days. Deployments are currently planned to average 240 days, and can be extended if circumstances require - 300+ days deployments are not unknown in recent years. So if the reactors are upsized sufficiently this would be doabl

        • To be clear, I wasn't suggesting that it was infeasible. I didn't know what the results would be when I started running numbers and I was actually pleasantly surprised by just how close to feasibility it is. The points I laid out were meant to show the current state of the technology ... not to shit all over it.

          Assuming all of the claims being made about it are true, it's a lot closer to reality than I would have thought and we should absolutely be trowing funding at it. It's unlikely to ever be as cheap

    • This technology has direct civil application by use of a nuclear power plant producing carbon neutral fuel for planes, train, and automobiles.
      No it has not as I pointed out already 10 times to you. That technology produces fuel that is twice as expensive than fuel from oil
      You would know that, if you actually had watched your movies and listened to the lectures.

      Is trolling your hobby?

  • Two little problems: (Score:5, Interesting)

    by Rick Schumann ( 4662797 ) on Sunday October 27, 2019 @02:29AM (#59351632) Journal
    1. Lasers are incredibly energy-inefficient.
    2. They mention satellites collecting solar energy and beaming it to Earth with lasers. What country in their right mind would not interpret such a thing as anything more than an orbiting laser weapon platform?

    One more thing: if you're going to have an orbiting satellite collect solar energy and beam it to Earth as a laser, use a solar-pumped type laser, at least that way you get rid of some of the conversion inefficiency.

    • What country in their right mind would not interpret such a thing as anything more than an orbiting laser weapon platform?

      The one that controls the whole system and has nothing to use them against as weapons.

    • Comment removed based on user account deletion

  • This seemed like cool technology...

    "First the first time, hundreds of watts of power were wirelessly transmitted hundreds of meters..."

    ...until I read the first fucking thing that came to their damn minds with this.

    "This could be the first step towards drones that never have to land..."

    If you're still dismissing an Orwellian future then pull your head out of your ass, because it's rather fucking obvious.

    • only those who imagine drones would be powered by a laser beam of hundreds of watts, that would set fires, damage power lines and kill wildlife aside from being hazard to pilots, need pull their head out of their ass. won't happen, can't happen

    • Re: (Score:2)

      by ceoyoyo ( 59147 )

      I don't think you'd want to use something like this for drones. It's much easier just to have two drones that relieve each other.

      It would be more useful to beam power to a spacecraft.

  • This is the peaceful concept that the mil sells in order to build a space laser weapon, the twist here vs the movie being that instead of a mobile laser source they've decided to just reflect it from space using an extensive network of thousands of LEO "broadband" satellites... they just need Kent working on a low weight and low cost targeting mirror to install in the birds.

    "We were trying to send power to a remote area of (some part of the Middle East) but due to uhhh... interference... maybe it was hacker

  • First time this was done? Try 1987 in Canada by microwave transmissions. https://friendsofcrc.ca/Projec... [friendsofcrc.ca]

  • Scale this up to miles and megawatts and stick it underground and maybe PG&E can stop starting fires or failing when there are high winds and/or earthquakes.

  • Power beaming isn't new, it's been around for decades. The only novel thing about this is that it looks like it's approaching commercial usability.
  • As the tech improves, I wonder if it could be used in conjunction with fiber optics to provide EMF free power transfer. I'm sure scientists might find that useful for certain types of sensors. If the power cuts immediately on interruption, then it could also be much safer if a line is cut. Even better, communication networks could carry their own power, like the old telephone network, and keep everybody talking during a general outage. Your GB of porn downloads could become GW of power!

  • While this is an interesting beginning it is not worth anything today or in the near future if at all.

    They used a 2 KILOWATT laser to transmit 400 watts. 2,000 Watts input, 400 watts output. A lose of energy of 80%.

    I wouldn't want to use a system so inefficient.

  • Hey boss, a flock of starlings just flew through the beam. It ain't pretty. Do we need to alert someone with the DoD or Navy??

    You bet. Colonel Sanders.

    • Just make sure there's a good enough exclusion zone for planes! And would silver ones create a cosmic mirror ball?
  • So this is how the US is going to weaponise space.....

Slashdot Top Deals

Ocean: A body of water occupying about two-thirds of a world made for man -- who has no gills. -- Ambrose Bierce

Close