# The Undersea Generator Nobody Has Built ($1000 challenge) Source: https://www.youtube.com/watch?v=6YODMrrVvPM Recap page: https://rapidrecap.app/video/6YODMrrVvPM Generated: 2026-02-20T21:40:50.038+00:00 --- ## Quick Overview The attempt to create a working seawater-based magnetohydrodynamic (MHD) generator failed because the initial design suffered from rapid electrode corrosion and insufficient magnetic field strength, resulting in only temporary and low voltage output (maxing around 450.9 mV), leading to the conclusion that the device acts as an "anti-generator" under test conditions. **Key Points:** - The initial MHD generator prototype produced a maximum voltage of 450.9 mV when saltwater flowed through it, but this output quickly dropped, leading the creator to call it an "anti-generator." - The primary issues identified after the first test were rapid electrode corrosion (oxidation observed in real-time on the multimeter) and insufficient magnetic field strength. - The creator built a second, physically larger version (Version 3) using a solid resin-printed body to improve flow, electrical isolation, and magnetic field strength by using steel plates on all four sides to focus the field. - To simulate ocean conditions, the test setup used water mixed with 135 grams of salt per gallon and an underwater pump with a diffuser. - The second, redesigned generator still failed to produce consistent power; any water flow obliterated the voltage output, confirming the design issues were not solely due to directional bias or electrode spacing. - The magnetic field was generated using N52 Neodymium magnets, which the creator noted were "terrifying to work with" due to their strength. ![Screenshot at 0:04: The initial prototype device, featuring multiple horizontal flow channels separated by metallic plates \(electrodes\) and magnetic material, is shown being submerged into the testing tank.](https://ss.rapidrecap.app/screens/6YODMrrVvPM/00-00-04.jpg) **Context:** The video documents an attempt to build a working, passive energy solution—a Magnetohydrodynamic (MHD) generator—that converts the kinetic energy of flowing saltwater into electricity using Lorentz's Law. This concept, where moving conductive fluid through a magnetic field induces a voltage, has been a subject of engineering interest for over 50 years. The creator builds and tests two prototypes, attempting to overcome inherent design challenges like electrical isolation and magnetic flux focusing. ## Detailed Analysis The creator attempts to build a functioning MHD generator to harness the energy from flowing saltwater, based on the principle of Lorentz's Law, where moving a conductive fluid (saltwater) across a magnetic field induces a voltage across electrodes placed in the fluid. The initial prototype, which used an assembly of layered flow channels and magnets, was tested by submerging it in saltwater (135g salt/gallon) circulated by an underwater pump. The first test yielded a temporary voltage of 450.9 mV, but the output immediately dropped, leading the creator to label it an "anti-generator." Subsequent analysis of the failed test revealed two major flaws: rapid oxidation (corrosion) of the electrodes in real-time, indicated by resistance readings climbing from 45.2 mV to 190.8 Ω, and insufficient magnetic field strength. The creator then designed a second, larger version (Version 3), which featured a solid resin-printed body with 50 millimeters of insulation to improve electrical isolation, and incorporated steel plates on all four sides to focus the N52 Neodymium magnetic field. However, testing Version 3 also failed; any water flow completely obliterated the already low voltage output. The creator concludes that despite the physics suggesting possibility, the practical challenges—specifically oxidation, electrical isolation, and magnet strength—make this design unviable for generating power from constantly flowing seawater. ### Initial MHD Thruster Test - Creator deploys a small device into saltwater flow, noting that similar concepts (MHD thrusters) successfully moved water previously. ### Generator Principle Explanation - Explaining that reversing the MHD thruster concept—forcing saltwater (a poorly conducting wire) through a strong magnetic field and measuring voltage across electrodes—should generate power via Lorentz's Law. ### Prototype Design & First Test - The first generator used three layers of magnets separated by electrodes, constructed using 3D-printed channels; the initial test yielded 450.9 mV, which immediately dropped, suggesting an 'anti-generator' effect. ### Failure Analysis - Key issues identified were electrode corrosion (oxidation shown on multimeter readings) and inadequate magnetic field strength; directional bias and spacing were ruled out as primary causes. ### Version 3 Redesign - A second, larger design was created using a solid resin-printed body to improve electrical isolation (adding 50mm insulation) and focusing the N52 Neodymium magnets with steel plates on all sides. ### Second Test & Conclusion - The improved Version 3 also failed dramatically when water flowed, obliterating the voltage output, reinforcing why MHD generators are not used in the open ocean due to these inherent engineering problems. ![Screenshot at 0:01: A small, multi-layered device, the first MHD generator prototype, is placed into a tank of water.](https://ss.rapidrecap.app/screens/6YODMrrVvPM/00-00-01.jpg) ![Screenshot at 0:05: Close-up view of the initial prototype showing the layered structure with electrode/magnetic material sections and flow channels.](https://ss.rapidrecap.app/screens/6YODMrrVvPM/00-00-05.jpg) ![Screenshot at 0:11: A diagram illustrating the initial setup for testing the reversed MHD principle in saltwater, showing dye tracing the flow path.](https://ss.rapidrecap.app/screens/6YODMrrVvPM/00-00-11.jpg) ![Screenshot at 0:45: A CAD rendering of the redesigned generator body, showing internal layers designed to house magnets and electrodes.](https://ss.rapidrecap.app/screens/6YODMrrVvPM/00-00-45.jpg) ![Screenshot at 1:17: The Keysight multimeter displaying a voltage output of 450.9 mV, indicating the maximum potential generated before the output collapsed.](https://ss.rapidrecap.app/screens/6YODMrrVvPM/00-01-17.jpg)