this video is sponsored by Hoy miles magnetic water pumps with no moving Parts recently took the Internet by storm with multi-million YouTube videos showing how to build one at home these pumps work on the physical principles called magnetohydrodynamics or mhd for short while most of these videos are actually fake mhd as a technology isn't and it's a real field of physics that we can use to not just make pumps but also propulsion systems for ships and spacecraft and even electrical power generators with no moving parts that work at a much higher efficiency than today's common power plant though this seems like the stuff of Science Fiction it's a technology that's been around since the early 20th century I'm talking about magnetohydrodynamics or MKBHD sorry no mhd the buzzing field of physics research that promises anything from Innovative thrusters for spacecraft and bladeless water pumps to a way to increase current power plant efficiency by over 50 percent and more than double the efficiency of PV solar this technology has been in the works for a decade but its time May finally have come okay so let's start with the basics and how it all works Magneto refers to magnets obviously Hydro refers to fluids and Dynamics refers to the forces of motion so mhd refers to using magnetism or electromagnetic forces to move fluids like water now this may sound a bit odd I mean we've all played with magnets and I doubt any of you have ever seen water or any other common fluid pulled or pushed by a magnet right well that's because water itself isn't a magnetic material this is where motion comes in even though water isn't magnetic there's still a way to make it move with a magnetic field and it's all based on electromagnetic induction and the lorentz force this is the same principle that makes electric motors work I promise I won't get too nitty-gritty on this one but in essence the Lorenz force is the force the charged particle Fields when it moves through a magnetic field so let's suppose we get a magnet on top and another one below a pool of conductive fluid and two electrodes with opposite charges on the side since the liquid is conductive there will be an electrical current moving horizontally between the sidewalls now we have both things we need for the lorentz force to act a magnetic field and the moving charges this will generate a force that pushes the liquid along the pool because Loren's force is perpendicular to both the magnetic field and the movement of the charged particles so the gist of mhd is to apply both magnetic field and an electric field what all this means is that it's possible to build an MHT pump given a strong enough magnet and a high enough current the awesome thing about it is that it works without any moving Parts this alone gives these pumps many advantages they're very simple and Compact and we can make them in any size we want from nanoscale to Industrial scale they're completely silent no moving parts means these pumps can work at much higher temperatures than normal pumps since you don't need to worry about material resistance at higher temperatures they're more reliable high efficiency because of they convert electrical energy into fluid motion directly with no propellers or compressors or anything else they need minimal maintenance and and they have the potential for a high power density we need very high magnetic fields so we need to use superconductor technology which isn't cheap but there is a really interesting new breakthrough we'll put links down below you're not going to want to miss there are other issues with flow instabilities in some cases and overall physics is very complex and it makes predicting how these pumps will work rather difficult these cars make these pumps impractical for our pools or home Water Systems however there are many industrial applications that are a perfect fit for example we can use them to pump molten Metals thousands of degrees in temperature remember that video we made several months ago about the solar cells that don't run on Sunshine well that system needed to pump molten 10 at over 2000 degrees Celsius an mhd pump would have been a way cleaner solution than the actual system that the researchers used other use cases include pumping molten salts or coolants and molten salt nuclear reactors and even micro scale pumps for lab on chip applications really amazing stuff okay now that we know how mhd pumps work you should be able to see why those viral YouTube videos are total scam if you already know what it is I encourage you to pause the video and leave a comment are you done all right so let's see if you got it right you'll notice right away that the pumps on these viral videos are missing a key component of the system the electrodes that generate the initial current inside the fluid without the current there is no initial movement of charged particles and no Lorenz force to move the fluid oh and then there is the fact that they're using fresh water which is a horrible conductor of electricity and they're using really weak electromagnets from a microwave Transformer coil or electric motor stator the peak magnetic field strength in a residential microwave oven is around 9. 2 times 10 to the negative 5 Teslas that's 50 000 times weaker than what you would typically need for a good pump so does that mean that mhd doesn't have a place in the world not at all you won't believe the other amazing applications this technology has especially in power generation now real quick let me tell you about our sponsor this week one of my favorites Hoy miles the micro inverter company that I chose for my entire solar system I went with Hoy Miles because I'm a fan of the benefits of micro inverters things like panel by panel inverting better performance with shade no single point of failure and longer service life but the cherry on top is their value proposition they're two to one four and one and even six to one inverters when you can invert two four or six panels with one inverter with all the benefits and significant savings here's my bill from April before we had solar turned on we used 1287 kilowatt hours and that cost around 685 dollars now here's our bill from June with solar The Joy miles app shows me I produced 1. 37 megawatt hours the house used 1140 so my bill negative 230 kilowatt hours and here so far in July we're on track for 1.
8 megawatt hours pretty amazing and saving 700 a month means I'll break even on my system in about three years I just love hoi Mouse far and they get a top recommendation from me check out hoymel's microphages for your system links in the description huge thanks to Hoy miles and you for supporting the show let's talk about propulsion so if you know you can make a pump that moves a fluid through a fixed point you can also fix the pump to an object and move the object through a fluid make it an mhd pump and you have an mhd propulsion system that has no moving Parts imagine them both that could Glide along the water without a propeller of any kind or a motor making noise well you won't have to because it's already been built see Mitsubishi heavy Industries built the Yamato one prototype in 1991 which was powered by an mhd propulsion system the system works just like an mhd pump with salt water as the conductive working fluid the ship only reaches a speed of around 8 knots 15 kilometers an hour and was ultimately discarded for several reasons the most important of which were the low efficiency of the drive the very expensive and heavy liquid helium cooled superconducting electromagnets and the fact that we need a massive diesel engine to produce the electrical power needed to run everything sort of defeating the whole purpose but mhd propulsion goes beyond boats on salt water any conductive fluid works with mhd and that includes hot plasma which is basically hot ionized gas since it's ionized the gas is full of electrically charged particles so it can conduct electricity and this is where things start to get very interesting for MHT first we can actually generate plasmas by ionizing the air with high frequency high voltage discharges which combine with an mhd system that can push the ionized air in One Direction you can generate thrust in the opposite direction with no moving Parts just electricity many researchers have proposed this type of mhd Drve Thruster as an engineless propulsion system for Aerospace craft with all sorts of futuristic shapes including flying saucers the Russians even built Ajax prototypes which use several mhd generators to ionize and suck in vast amounts of rarefied air to run an air fed Ramjet at Heights of over two hundred thousand feet around three times higher than the best fighter jets mhg propulsion is awesome and we should make an entire episode about it if you'd want us to make that episode sound off in the comments below but I want to talk more about something even better that could impact everyday people like you and me MHT power generation you know how we can use an electric motor in reverse and make it spin to get a generator well we can do the exact same thing with an mhd propulsion system if we take a conductive fluid and force it through a magnetic field Faraday's law of induction will kick in and will generate electricity any conductive fluid works but its plasma that is the most promising you see one very easy way to produce plasma is through heat when we burn natural gas for example the air in and around the flame gets ionized and it turns into a plasma run that stream of plasma through a magnetic field and it generates DC voltage directly this is completely mind-blowing because of the impressive increase in a efficiency this would have a normal Power Plant we burn fossil fuels to generate heat then convert that heat into mechanical energy by spinning a turbine and then turn that mechanical energy into electrical energy using a generator and an alternator it's complicated each energy conversion loses a little bit of efficiency and lowers the overall efficiency pretty significantly here we use hot plasma and magnets to turn thermal energy directly into electricity in one Fell Swoop but that's not even the best part since there are no moving parts we don't need to worry about material resistance of high temperatures so while a normal gas fire turbine can run at a maximum temperature of around 1300 degrees Celsius and mhd Generator can run at a scorching 3000 degrees Celsius so what gives well here's the thing all thermal machines have a limited maximum theoretical efficiency which depends on the temperature difference between the hot source and the ambient temperature that efficiency is given by the following equation so the higher the hot temperature and the lower the cold temperature the higher the overall efficiency for a normal combined cycle gas power plant running around 1573 Kelvin and discharging the exhaust at 300 Kelvin the maximum efficiency is around 0. 809 or about 81 percent which isn't too bad in reality due to all the losses and the energy conversions you only get an efficiency of between 45 and 57 percent but for an MHT generator working at 3273 Kelvin the efficiency is around 0.
