Lightning engineer Allen Hall will be joining me for a livestream on August 9/10 depending on your timezone: ru-vid.comsq5qZzVPLTY Set a reminder to join us live or leave your questions or suggestions for better/ cooler ways to protect wind turbines from lightning here in the comments.
Carbon fiber airplane manufacturers have shown, utilizing a layered form of protection from lightning strikes can be achieved. Including external protections such as coatings, plus internal protection, such as layers of metal. A very robust form of lightning protection is created. So what added value do we get by knowing the nature of lightning?
Why don't they just use mesh like conductive light structure within the case of the blade that lead to main cable inside with many connections along the blade. Simple like Faraday cage.
Some years ago i worked with this issue. Due to self induction of the lightning wire inside the turbine blade and the the high current gradient from some lightning flashes there vill appear a huge voltage drop from top to botton in the wing. eg 100 kV to 1MegaVolt. It is difficult to isolate a Carbon conductor inside the blade against the huge voltage drop, therefore it is wise to find a way to electricaly connect the carbon fiber to the lightning wire throughout the turbineblade to avoid arcing.
There are a few methodologies that carbon fiber airplane manufacturers are utilizing.... Such as conductive materials interwoven into the airplane or in this case the blade.... or conductive coatings.... Actually I was thinking of a Faraday cage shield initially.... There are not that many original ideas.... We just end up, improving upon old ones, If we are lucky....
Thanks for the insight@@nc3826. One thought that springs to mind is what capacity of the wire of the mesh is required? Interweaving a mesh with a large enough guage wire to carry the energy will inevitably lead at some point an unacceptable increase in the weight of the blade. This then brings it's own issues with WTG efficiency and having to up-rev the support structures which hold the blade. As Rosie mentioned, it's an ongoing area of development that is struggling to keep up with the pace of WTG development (blade tip height and blade material).
I have terrible lightning issues at my house and shop. It's a regular occurrence to have sensitive equipment damaged during storms. When I first moved into my house I saw 100mm sparks jump between the copper pipes for my hot water heating zones. I've had equipment blown off the wall because lightning entered through ethernet cables. Everything has since been bonded, all the pipes at all four corners of my house, and installed grounding plates at each corner of my house in addition to the grounding rod required by code. And a few grounding plates at my shop. All outdoor ethernet has been replaced with fibre. I also installed metal roofs on both buildings, thinking if grounded these would be somewhat like a Faraday cage. I don't know if that was misguided. I also have maybe 200-300 clip-on ferrites installed on basically everything that plugs in and in the panels, plus I've wound loops around ferrite torroids for all permanently installed equipment. And the usual MOV suppressors on every outlet. Is there anything else that can be done? Have I made mistakes?
Do MOV suppressors take the loading of a nearby strike? They look quite flimsy. I've never had to deal with lightning & I'm definitely no expert but as you saw with your water pipes very high Voltages will jump gaps if not insulated so deliberately removing insulation from incoming cables where they're close to heavy-duty earths might be helpful. There's probably 2 busbars in your fuse box, one for each supply wire, an earthed bar beside each would give a point for high-Voltage flashover to occur, or perhaps an earthed box with the supply cable running through & uninsulated in the middle. Obviously _very_ clearly labelled & probably closed with security screws.
I’ve seen high speed video experiments where a positive charge is produced from an object about to be struck actually reaching out and grabbing the lightning strike , there are even some rock structures that start to hum then release upwards lightening.
Very enLightning! :) I'd never guess this was happening so often. that was very interesting to learn. Can you go deeper on the subject of fluid hot air? This gave me a better understanding about lightning. Thank you for sharing!
Lightning is plasma - the 4th state of matter. The atoms and molecules are super-heated and very energetic....and conductive. Because it is conductive it can carry current and be influenced by magnetic and electric fields. Plasma can also be pushed around by the wind. It's hard to visualized by lightning is easily pushed around by the wind and super sensitive to electric and magnetic fields nearby.
@@WeatherGuardLightningTech does this suggest conductive &/or magnetic shapes which might direct strikes away or towards specific points? Perhaps some sort of direction of the blade tip vortex?
What type of grounding system do wind turbines use? When I was a broadcast engineer, besides having lightning rods atop the towers, we used buried radial wires. AM stations already have a robust ground system. However, on FM, TV, and communications towers, we use ground radial systems specifically to dissipate the energy of lightning strikes.
Wind turbines are connected to the earth via ground rods and generally the rebar in the concrete pads. The industry has requirements for bonding that most operators follow. In some parts of the world it is really difficult to get a stable ground - particularly rocky or mountainous areas - and extra work is needed to get grounded.
Some new info for you,,, a wind farm in my area was sold to the landholder after it had been in operation for 23yrs. Now the landholder has since sold his farm because he found the costs to maintain the wind farm was larger than the returns it earned. SO THE INSTALLERS RECOVERED THE COSTS TO FIT THE SYSTEM AND A HANDSOME RETURN ON TOP & NO COSTS TO REMEDIATE THE AREA AND PROFIT FROM ITS SALE !! yes thats the game watch it roll out in your area
Laser-guided lightning is still relatively new and expensive. The recent experiments in Switzerland required blocking off the airspace so that the lasers didn't affect pilots!
What about a sacrificial drone just above the blade radius tethered to a conductor outside the turbine housing with it's power lead. Perhaps it would create a preferred path for the strike. The drone could stay up indefinitely during a storm because of the supplied power. The tether combined with high wind may not make this a viable solution. As well as less conductivity compared to a wet carbon fibre reinforce blade.
NASA 100% protect their space rockets on the launch pad from being struck by providing a better target above the rocket, so the answer is yes. I think the real question is if it would be cheaper to do so?
@@nigels.6051 The launch pads are relatively simple to protect - put up a couple taller towers and connect them with catenary wires. Works pretty well to protect a small area. Wind farms are pretty massive - covering several miles. Difficult and expensive to put up tall towers next to every wind turbine - especially on the more remote/mountaintop locations.
@@WeatherGuardLightningTech NASA has the problem that they need to leave a hole in the top to let the rocket fly through. For a wind turbine I imagine it can be done with a single tower, which the wind turbines already have, although not tall enough. But presumably this has been thought about and not implemented for good reason? Is it worth parking the turbine while there is lightning overhead - improve the chances of it going for the lightning rod on the tower instead of a non-conductive blade.
One thing I don't think very many people know. outside of electricians, it's everything is conductive at a certain voltage. Even non Conductive things like plastic Ceramic glass It all has carbon in it which can be conductive.
G'day, Yay Team ! Lightning is weird, but I never previously considered the concept of it being a Plasma which is Hot Air and Air is a Fluid which flows around Surfaces according to the Laws of Coanda and Bernoulli - so the Lightning is Blowin' in the Wind..., and Eddying in the Turbulence Of the Blade-tip Vortices... Yikes ! Good luck trying to control the Connection and direct the Flow of Current, under such a plethora of Variable factors - Especially in a Structure featuring conductive Carbon Fibre... One wonders how the increasing frequency and increasing intensity of the record-breaking Extreme Weather Events will be featuring Lightning Strikes with proportionally more Volts, extra Amps, and bonus additional Milliseconds of Peak-Flow...? It's now about ten years since Hailstones first grew up from "Golfball-sized" making the National TV News, to "Hailstones as big as Oranges", which killed a score of sheep, dozens of Kangaroos, and two Horses out around Narromine... Warmer, wetter Air can contain more Thermal Energy - so the Vertically moving Airmasses are apparently being effectively fed more power ; so the Hailstones are going up & down inside the tops of the Clouds many more times, accreting more Ice every cycle..., before finally becoming sufficiently heavy that the Updrafts can no longer keep them aloft... Are the bigger better upsized Stormclouds, which now deliver bigger better heavier and more energetic Hailstones (even unto the infamous Mega Cryo-Meteors - Hailstones as big as Watermelons !)..., also introducing bigger better shinier Lightning Bolts with added extra Current, boosted Volts and longer lasting Strikes - all growing with every passing year, as the Atmosphere continues to heat up...? How does Bushfire Smoke effect the Blades' Lightning-Protection System's performance - does the Smoke leave any Deposit on the Leading Edge of the Blades, and if so then what does a layer congealed Tar, with microparticles of Ash and Soot (Carbon) do to the Conductivity of the Smoke-stained Leading-Edges (?), One Wonders.... Such is life, Have a good one... Stay safe, ;-p Ciao !
Carbon fiber aircraft use metal mesh on the exterior to minimize burning damage where lightning attaches. Plus the carbon fiber on commercial aircraft is high quality material and relatively thick. This makes it pretty tolerant of carrying lightning currents. Carbon fiber aircraft still have a significant amount of metal - mostly aluminum - to act as a current path and electrical power ground.
Oh, no explosions :-( I'm disappointed now :'-( Still, seems like a fascinating topic. Are there camera triggers which sense the electrical field build-up a few seconds before the discharge? I'm sure high-speed video viewed from perhaps the far end of the nacelle would help understand the detail of what's happening
Maybe "Passive" lightning protection isn't up to the task, especially with the large lead times in testing. You never mentioned in the video about "active" lightning protection. Actively Charging the Wind Turbine Blades and Structure to reduce the electrical potential between the clouds and Turbine, but not enough as to cause a discharge between from the Structure to the ground. Making the Turbine a less attractive target, compared to the surrounding area. Or, a Dual Charge Approach. Adding another "active" lightning protection like adding an "charged" attractive lighting rod to the top of the tower. Actively charging the attractive rod to increase the electrical potential and number of lightning strikes, while actively charging the structure to reduce electrical potential from cloud to Turbine.
From my little knowledge about sparks I know that the air becomes conductive when heated. A DC spark can be made very long but must have a close contact to start. Is there a possibility that the blades either ionise or heat the air at the high speed? Or maybe it is a change of humidity. By the way I don't think the lightning only takes the way of the least resistance. The current from the lightning MAINLY take way of least resistance but takes all possible ways.
Lightning heats the air to around 10,000 Celsius in about 1/100,000 the of a second. Lightning doesn’t necessarily find the least resistive path - it just needs a path. Lightning rarely takes a straight line path - it winds and twists about itself for miles.
Can the blades be retrofitted with a conductive mesh bonded to the surface and connected to the ground lead in order to save invested funds from being lost all together? How much would the extra weight affect the blades and the whole system?
To bond on mesh a couple of big tasks - cleaning the surface so it will take the adhesive/mesh, cutting and splicing the mesh so it lays flat, vacuum bagging the whole area, pulling a vacuum and injecting the area with resin. Throw some heat blankets overtop to accelerate the cure. Pull off the bag and inspect for the problem areas - Rosie will attest that there are always problem areas - and start repairing / patching until the whole area is covered properly with mesh. It’s a big job!
@@agw5425most wind farms in the US will replace their blades in the next 5 years due to the IRA bill. It’s the perfect time to improve their LPS system. The upgraded turbines will produce with more with less downtime!😊
Very interesting! Surely there must be a lot in common with aircraft fuselage and wings which also have to withstand lightning strikes on average once per year. I’ve experienced one! In the case of aircraft built using composites, like the Boeing 787 they have a continuous layer of copper mesh on the outside of the whole aircraft. Why don’t wind turbines follow this practice rather than trying to predict where light will strike?
Aircraft and wind turbines are similar to a point. Aircraft have governmental regulations regarding safety and the aircraft designers are very cautious. Copper mesh is relatively expensive and can be difficult to work with. Plus, when it is damaged by lightning it is cumbersome to repair. Wind turbines do not (generally) have regulations regarding lightning and the copper mesh expense doesn't work for budgets. Plus, aircraft have a huge amount of oversight and inspections which identify and repair mesh damage. Wind turbines are not serviced as frequently.
I am an Electrical Engineer and I have often work on systems that have Mechanical Engineering leads that take a mechanical centric approach to the System Design and often (because of their limited Electrical experience). This often leads to issues like you described. When you first mentioned that they thought the blades would not get struck because they were insulators - my brain immediately thought "that was stupid". 1) Air is an insulator too so it is all relative 2) Electricity travels more easily on surfaces than through air 3) Water will accumulate on the blades during a storm and that will create a travel path 4) (probably the most important) Residue will build up on the blades from the rain and that will include salts and minerals that are very conductive when dissolved in rain.
As a windturbine electric technician, i can agree that almost every part has some form of lightning protection, even the Internet cables. At least @ Nordex Turbine's
Wind turbines have improved their lightning protection a great amount in about 15 years. Turbines built in the early 2000's didn't have much protection.
Unfortunately the wind turbines without protection did very poorly in service. Blades were damaged/destroyed and the electrical equipment in the nacelles were exposed to massive lightning voltages that frequently damaged equipment.
To this layman, at least, a wind turbine blade seems similar to a composite glider wing. There was a glider strike in the UK in 1999 where the aircraft was essentially blown apart by the rapidly-expanding air, and the magnetic fields involved were strong enough to completely crush the aileron control rods: www.gov.uk/aaib-reports/schleicher-ask-21-two-seat-glider-17-april-1999
A wind turbine blade is similar to a glider wing. The magnetic fields involved in the 1999 strikes were massive. We had difficulty trying to recreate that damage in the lightning laboratories!
What do the brushes between the wiring in the blade blade and the nacelle look like? In theory you could have a small gap which the lightning jumps across because the strikes are uncommon so there's no friction. Or it could go through the hub & the bearings instead.
Very interesting Rosie!!! My encounter with lightning, as a Central Florida resident has been 2 times with a total cost of $3000 for the electronics in the house. Went through 2 whole house surge suppressors and the current one is a commercial unit. Power lines still getting hit, but seems to be working.... time will tell. Also redid the service panel ground system. Fingers crossed. Amazing how lightning can wipe things out is a fraction of a second. Great video
What if we could tame lightning for something useful? Many years ago, Union Carbide (Now part of DOW) was manufacturing pure carbon electric thermal induction rods. Then, when the world’s steel production shifted to China, they had a lot these rods, which are used to convert electricity into heat to melt iron ore in steel mill blast furnaces. So, Union Carbide invented a SMALL steel mill blast furnace, to install in all hospitals, to incinerate all hospital wastes, which hospitals paid waste disposal companies to dispose of, but a lot of medical waste ended up being dumped in the ocean, and washed up on seashores endangering vacationers. Their mini-blast furnace would use these carbon rods, to superheat a pool of molten steel to completely destroy and incinerate ALL hospital wastes onsite, with the waste heat being used to heat the hospital, and heat the hospital hot water, with fused stone slags being periodically removed from these units, to become bricks or stone sea jetties. And because it had NASA’s space shuttle tiles insulation, it would always keep the pool of steel molten, by preventing the thermal heat from dispersing. BUT, this thing never caught, because the electricity needed to make its carbon rods heat up was just too expensive, they didn’t want to pay such an ENORMOUS electric bill. BUT, what if we could ground lightning bolts from the many lightning rods on the tall buildings of cities, or from lightning strikes on tall windmills, into such hospital miniature blast furnaces? No more electric bill, and such units could also be used to destroy many types of toxic wastes, or melt down various metal junk for recycling as well.
I'd expect a test setup would be more realistic if the blade was both wet and dirty too. Years of oil, grease, rust and dirt stains must surely affect a blade's surface conductivity.
I want to read more about this! Like the level of scientific white paper that makes most people's mind seize up (I have weird hobbies). I also like to research current scientific methodology before making suggestions that have already been tried or are scientifically proven as idiotic. (i was supposed to be some sort of engineer but ¢¢¢😔)
I love your work. However, I'd appreciatte if you can decrease your speed at talking a little bit. It could be challenging for non native english speakers like me to follow you up.
As wind blades are reaching lengths greater than 100m, putting a lightning rod nearby or on top of the nacelle is expensive and a little tricky. It adds costs and can disturb airflow. Right now - wind turbine manufacturers are bleeding cash and can’t afford additional lightning protection…
Perhaps one day it will be possible to HARVEST the energy of the lightning strikes, so that when wind turbines are halted due to a storm, energy may still flow from the farm to the grid, only from a different source.
The boring engineering answer to that is that since it's such a short duration there isn't actually much energy in a strike despite the high power. Plus it's very infrequent so wouldn't really be worth the cost of the equipment.
@@EngineeringwithRosie there is a place in South America where a feature of the geography means there is near-continuous lightning "Catatumbo lightning (Spanish: Relámpago del Catatumbo)[1] is an atmospheric phenomenon that occurs over the mouth of the Catatumbo River where it empties into Lake Maracaibo in Venezuela. Catatumbo means "House of Thunder" in the language of the Bari people.[2] It originates from a mass of storm clouds at an altitude of more than 1 km (0.6 mi), and occurs for 140 to 160 nights a year, nine hours per day, and with lightning flashes from 16 to 40 times per minute.[3] It occurs over and around Lake Maracaibo, typically over a bog area formed where the Catatumbo River flows into the lake.[4] The phenomenon sees the highest density of lightning in the world, at 250 per km2.[5]" - Wikipedia Harvesting it would probably be an ecological disaster but the principle could surely be engineered elsewhere? (At least for fun with jumping gauges even if not for much practical benefit). There are several predictable named winds around the world, Chinook & Mistral spring instantly to mind, but it seems the wind has to be wet.
One more comment then I'll stop. I've worked on large equipment where static discharge and grounding currents are quite a serious consideration with respect to bearing damage. Even relatively small currents can do a number on bearing balls/rollers and raceways. Think of an EDM machine, but the inside of your bearings being etched. Even with a slipring to ground bypassing the bearings, I'm sure still a very substantial current passes through the bearings. Is this a concern?
Yes - you are correct. Some amount of lightning current is flowing through the bearings and raceways. This current will pit metals and create weak spots that will force an early failure. Wind turbine designers try to give the lightning current alternate paths around the bearing/raceways - not always successfully!
Seems that many modern aircraft (b777, a350) are large composite structures distorting airflow approaching mach 1.0. I wonder what cross-over exists in the science and modelling?
Modeling of lightning in airflow is becoming more common in aerospace. Researchers in France have produced interesting results. More recently MIT has created an Aerospace Plasma group which has focused on pre-lightning charging effects to prevent strike to aircraft and wind turbines.
Thank you for your videos. You know there are going to be several thousand viewers who don't understand that the ground wire shown in the graphic is conceptual and will wonder why the 3 cables don't braid themselves together as the blades spin. In your follow up a picture or video clip of where the rotating assembly transfers 3 cables to 1 via a hub would be enlightening.🙂
Airliners have the same problem and with modern composites used in wing and fuselage construction, you can't rely on the low electrical resistance and high current carrying capability of an aluminium alloy airframe. Likewise, expanded copper or aluminum mesh is incorporated into the structure.
Correct! Wind turbine blades are relatively inexpensive structures compared to aircraft wings and fuselages. Turbines blades are also mass produced. The costs and problems with expanded copper/aluminum mesh is avoided by most blade manufacturers.
Are many bearing failures caused by lightning strikes? Tiny arcs between bearing rollers and rings will pit the surfaces leading to cascading damage. Presumably the rotating shaft is grounded via a slipring but avoiding *any* current going through the bearings must be *another* difficult problem.
Yes - bearings can be pitted by lightning currents or even static electricity discharges. This will lead to premature failures that are hard to identify by mechanics. Aircraft engines are rebuilt after lightning strikes because the bearings and raceways are pitted.
I wonder how they connect the "wire/mesh" from the rotating blades to the turbine body. Are they using carbon brushes and copper commutators, or there is something newer/better?
A few people have asked that. It's a different design for each manufacturer. We can talk about it in the livestream, I am pretty sure Allen knows all about that.
I live in the South of Scotland where the Firth of Forth offshore wind farm is about to open to join 30 on shore farms in the Scottish Borders. I have seen lightning strike a turbine on a hill above Eyemouth where I live and it didn't seemed damaged.
Thank goodness the lightning protection systems work relatively well. The more wind turbines we install in the water the more we learn about lightning!
Wow! I just instantly just assumed cable to tip, slip ring, earth it and you're done but turbines, wings and propellers are crazy complex and explained like that I can well see the issue in trying to model where a bolt is likely to attach. Air pressure and in turn temperature and conductivity would have to look crazy around the tips of the blades without anything else thats going on....
That's the problem with wind turbine lightning protection. To properly solve the issue, it will take a combination of electrical theory, electromagnetics, thermodynamics, aerodynamics, and plasma physics.
@@WeatherGuardLightningTech This is engineering, it's not necessary to know every last precise detail to solve the problem, just pick up on a couple of facets & work from there. We know an electrical field builds up before a strike, I understand that when graphed it has a predictable pattern & is detectable with an _electroscope_ (yes I know, Victorian-era tech, but it's reliable & everyone's seen one at school). This could be a trigger for a leading-edge slat or just an air or water blast to pop out & disrupt the airflow into massive vortices deflecting the formation of a plasma. If left fully analogue & at least mostly mechanical it should be fast enough to be useful, self-retracting & tough enough to withstand strikes that still get through. Consideration might be given to the idea that a superheated plasma discharge inches from the blade might stress the blade.
Interweaving some type of metal, is the main strategy that carbon fiber airline manufacturing is utilizing for lightning protection. And secondarily conductive coatings. So it seems like the same applications will be applicable to wind turbine blades too? Personally I would like to see aluminum layers added, as a structural element. Which should be a more economical and recyclable alternative. But when additive manufacturing matures, I'm hoping complex aluminum matrices will be feasible to manufacture at scale and have a sufficient strength to weight ratio. To replace carbon fiber and fiberglass wind turbine blades, Which also should be inherently more protected from lightning damage. Plus at some point we need to utilize lightning as a resource.... I know it's cliche, but every problem is just an opportunity in disguise.... At some point in time..... Lastly thank you Rosie you make all these topics fascinating....
Great comment. I'll note it down for the livestream because there's a lot there! One quick comment on aluminium: that used to be the material of choice for blades before we swapped to fibreglass. The main problem was fatigue damage. Aluminium is generally not great under fatigue loading.
We were involved in a number of aerospace efforts using carbon fiber interwoven with a metal - preferably a metal that didn't corrode when in contact with carbon fiber! Aluminum and carbon fiber create a fantastic galvanic battery. As Rosie will attest, composites have so many advantages over metals.
@@EngineeringwithRosie 'Fatigue failure of the de Havilland comet' Tragically proved the aluminum fatigue issue. But it was still used to build planes for the coming decades. And composite materials such as fiberglass and carbon fiber eventually delaminate. But the blades don't have to last forever. A good engineer designs something, so that it lasts one day longer than its usable life, right? My main concern is using a material that will be economically viable to recycle. But I know this is just me tilting at windmills. Since what I'm suggesting does not seem currently feasible. (This conversation reminds me why I love my steel bike so much) Sorry for my long-winded replies, keep up the inspirational good work, Rosie.
@@WeatherGuardLightningTech I was mostly suggesting utilizing aluminum with fiberglass.... and i'm aware of the aluminum carbon fiber galvanic issue, but used in conjunction with a layer of fiberglass offer superior protection against galvanic corrosion. Another option to prevent corrosion between carbon fiber and aluminum is to encapsulate the bonded areas where neither water or moisture in the air can get to the bonded surfaces. these methodologies have been used for decades with carbon fiber aluminum Interfacing in bikes. And when composites become economically viable to recycle.... I'll stop hoping that metals become a viable option again.... Again I know it's unrealistic at this point in time, for this application ... Thank you for your input....
Wind turbine tests are mainly about structural integrity and system performance. Lightning strikes to test turbines are just a bonus. Most of the lightning testing happens in laboratories. Placing test turbines in strong lightning locations would definitely help find issues early.
We could capture the energy but it is surprisingly a small amount. Lightning is powerful not due to the total energy but rather the rate at which the energy is deposited.
Rosie: Really enjoyed this video. Glad to see you are working with Allen on this. I worked with him many years ago on some new aircraft design projects. He is one of the best. Frank V.
Normally, fiberglass is an excellent insulator so lightning wouldn't strike it. There must be other, conductive materials, in the blade construction to allow lightning strike
The "lightning follows the path of least resistance" canard has always bugged me. I learnt ohms law somewhere around 9th grade.... Lightning is electricity and electricity takes ALL available paths simultaneously. Now an ionization channel is going to be the main path of lightning in a poorly conducting medium ... but given the potential energies (and just plain potentials) in lightning, anything in the close proximity of a lightning strike is in danger. (You're still relatively safe inside a (metal) body car, as the amount of metal around you is fairly substantial). As I understand in buildings the conductive path is usually routed through a girder or standpipe ... a *huge* amount of metal. Inside of a blade, where weight is a consideration, I'm presuming the conductor is relatively small. The problem is as you mention specific energy. Electricity follows the *outside* of any conductor ... but in any volume/mass of conductor there are only a limited number of free electrons to carry electricity. ... Sure it will move inwards to be conducted as the outer layers saturate, but it only does so by overcoming its own electrostatic potential ... which on a small conductor is HUGE ... hence the overages will spark out . I would suggest that the solution would be multiple conductors with embedded highly conductive (aluminum probably) mesh around them and ideally through the material of the blade. Carbon fiber is a good conductor, but you have the problem of the outer layer being the only real conductive path, when the charge saturates the outer layer's free electrons, it heats. You need a mesh of more conductive material inside so there isn't a saturated outer layer conducting the electricity. Now all of this speculation from a once, too long ago now, physics student, lazing around the peanut gallery. The ideas need to be tested (or maybe already have and then discarded) but I'm throwing it out among the peanut shells for anyone to pick up as they choose.
Good observations - you are on the right path. Putting carbon in a blade next to a wire / conductor is a massive problem. They must be connected together or widely separated. As Rosie described - if there is an electrical spark between the two the carbon can be damaged. As the carbon is carry most of the mechanical load this damage can cause blade failure! Such a huge problem! Blade designers are trying new designs at the moment - we shall see!
@@WeatherGuardLightningTech Don't know how practical it would be, especially with cost considerations, but it seems to me that the best solution would be to move the main conductive path outside of the blade structure, making he *outside* of the blade conductive as well with connections between at frequent regular intervals. (or better yet two, one near either edge where the ES potentials will be strongest). Now anything outside the blade is going to have *some* aerodynamic interference which will probably be small and manageable, but the mechanical resonance problems in higher wind situations would be problematic. Still if you're expecting hundreds of strikes throughout the blade's lifetime, it's probably worth the effort to look for a "best" solution. I think part of the real problem, that I haven't heard talked about is that these blades are moving through air that even naturally has a rather large voltage differential. It is almost by definition picking up charge and carrying it across different amounts of ionization ... which is how a Van de Graff generator works. Has any one documented "clear sky lightning" from these beasts? I'll bet a substantial amount that it happens, and won't be surprised if it's really fairly common if someone looks. (I'm also wondering if some of the "lightning" damage isn't caused by the stress on the materials of carrying these possibly quite substantial charges almost continuously for years even when there is no observed "lightning"). Hmmm. Have your scientists talked to your repair techs? I'll bet the techs have procedures for making sure they dissipate any charge around them while working ... getting nasty shocks a few hundred feet in the air will be educational. You need a multi-approach solution. The range of energies in a lightning strike is so wide that it's impossible to account for the high end - I've read there have been observed bolts that can rival a small nuke (quite rare and usually as sprites rather than ground), but you still have to deal with the possibility of larger than normal. But at the same time it's best to dissipate the likelihood of strikes generally, perhaps a field of regularly spaced poles (spikes) around them reaching a substantial height or even a barbed wire (points to dissipate static charge) net (perhaps one strand every 10 meters or so) to minimize the voltage differential from ground to sky. Basically the interaction of electrostatics and atmosphere is something that seems to be poorly understood. I have a hunch that tornado formation, and even summer dust devils as well as larger weather movements have a fair amount to do with ionized air movements as much as from pure vortex mechanics.
Hi Rosie, Thanks for your enlightening and thought provoking video (pun intended!) I wonder if taking the opposite approach, to tackle lightning damage, might be viable? What if we retrofitted wind farms with lightning inducing structures that help farm the enormous power of lightning, and in doing so allow the lightning to easily flow safely to earth rather than damaging the existing wind turbines already in situ. I wonder how massive and expensive these structures would need to be and if it could be modelled? If it were possible to divert the lightning strikes to earth before flooding the generators, then one candidate for these mega structures could be vertical axis wind turbines made from readily available, highly conductive aluminium alloy. Despite generating a fraction of the electricity of HAWTs, these lightning inducing Mega VAWTs might offer an easily maintainable, heavy duty option to accompany the existing array? I wonder if the Mega VAWT's generators, and other susceptible electrical components, could be housed in giant Faraday-caged concrete foundations. This style of Mega VAWTs might then be significantly more serviceable than the HAWT with their sky high generators, since there would be no need to scale mega structures 100's of feet from the ground, just to perform preventative maintenance or repairs to the business end of the turbine. I'm also curious about progress with lightning farming. Maybe we should be thinking about lightning farms that include wind turbines rather than the other way around? My initial thoughts are that if we could develop mega powerful hyper capacitors, that could actually handle the immense instantaneous power of the lightning strikes, then we could proactively harvest the lightning, which would otherwise pose a threat to the HAWTs already in situ. Theoretically, stored energy in the hyper capacitors could be used to feed the grid when the wind drops. That would be a truly awesome achievement! If this technology were developed, it could present a compelling business case. The potential reduction in maintenance and repair costs, combined with the extended lifespan of wind farm investments, could be significant. If there was also potential for additional revenue from increased consistent supply to the grid from the modernised wind farm, then I wonder if that would add up to a cost effective solution?🧐 app.runwayml.com/creation/67d7e16d-a293-42a6-9452-ac96e6ca70e4 I'd be delighted to know your thoughts. Kind regards, Richard
I laughed so much watching this. Thank you! In our part of the world the lightning problem was solved in the 1980s. The American solution shown 6:47 only works for a wind turbine that's not running (assumably an American designed wind turbine). If the wind turbine was actually running then the wing to ground cable would be twisted and twisted and finally brake.
Would it be possible to harness the probability of lighting strikes to charge capacitors instead? Basically try and encourage strikes to charge a storage medium? Turning the problem into a solution or benefit? Could be called a LightningVane Turbine or ThunderWind Generator?
At 2:35, you said "That's negative lightning, which usually flows from ground to a cloud. Positive lightning from cloud to ground tends to be a single leader with variable branching. It doesn't really branch as positive lightning is basically hoovering electrons as it moves." This seems confusing when considering the terminology for electric current flow, or electron flow .. Seems that the positive and negative herein only refers to the "initiator" of the lightning strike, irrespective of the current/electron flows, correct ? coming from sky is positive, from down earth is negative .. sounds religious ..😀😀 Also, is it always electrons from earth flowing upwards to the clouds ?
Always interesting to change perspectives, but this particular one (~3:50) shows the big empty room she's talking to. I'm no videographer, but I think it would be better to green-screen her standing in a power distribution substation (if not actually standing in one...) Otherwise enjoying the lesson.
Can you do something on transmission please. Dr Robert Barr, electrical engineering australia nuclear power promoter. And Robert Parker, Civil Engineer and nuclear promoter. The cost of transmission lines for solar farms is prohibitively expensive they say, but the same difficulty exists for all concentrated central electric power generation. Including wind farms. Millions of klm of poles and wires to every street and home and building and etc. Thousands of kilometres of transmission lines. Massive increase in electricity demand means massive increase in this fragile infrastructure. Many think this is the critical cost limitation in the renewable energy future. Your team will do a wonderful educational service. Personally I think that the existing solar panel support structure is our existing rooftops. All 20million are connected to the existing national transmission grid. EV big batteries are coming and will supply a massive storage system, a dispersed storage system and will protect the existing national grid by unloading all buildings demand on the national grid. New thinking please. Horse and cart thinking is dangerous. 😊😊
A lot of lightning strikes to wind turbines are upward ground-to-cloud flashes. The examples from Tom Warner that you showed were upwards. You mentioned that the rotating blades makes them more susceptible to lightning impacts. The reason for that, at least as far as we know, is that the moving blades outrun corona discharges that act to dampen the electric field on stationary objects. Lightning flashes to wind turbines have caught the attention of lightning researchers in another way, because they seem to be the culprit for a lot of thundersnow. It appears that they will initiate upward flashes into winter clouds that aren't quite electrified to produce their own lightning flashes. The charges on those clouds are likely much lower in elevation, and the turbine blades without their corona shields evidently reach high enough to trigger lightning. Since upward lightning is strongly dependent on object height, the increasing height of turbines is almost certainly contributing to the higher frequency of damage to newer systems.
Rosie, question for the livestream, if carbon fibers electrical conductivity is potentially a contributing factor, is electrically insulating the blade from conducting to earth a solution? I’m thinking that airplanes get hit by lightning all the time and the modem aircraft are using carbon fiber shells as highlighted by the Qatar airbus lawsuits. It would be a degree of complexity at the hub to insulate while allowing the lightning conductor to transmit to ground, but similar engineering problems have been solved in rotating work platforms which have power and controls in the non rotating base. Curious to hear the weather guards experience based thoughts on this if only to see if airplanes are lucky and turbines unlucky !!
Is there a video on wind turbines vs tornadoes... There are videos on yt where you can see wind turbines getting hit by tornadoes. But i don't know that design measures that could be implemented to reduce the risk of failure.
Maybe??! AI is (hopefully) using the published scientific papers to help engineers on design decisions. The problem is that lightning is still not completely understood by scientists. So, AI (LLM) can only (today) summarize the data that has already been published. Hopefully future iterations of AI can help!
Could you in theory reduce lightning strikes a great deal by having the nacelle be part way up a much larger tapering spike, whose tip is higher than the blade tips when they cross vertical? Would it just be cost thag prevents this?
@@WeatherGuardLightningTech Good to know my thoughts aren't entirely dumb haha, I was imagining the entire structure looking similar to the Dublin Spire monument, with the nacelle about half way up. I'd imagine could be done, yes, costly? Probably. Id be interested to know how it would affect the long term operational costs though.
A similar idea has actually been tried. Guess what? The turbine blades still go POW!. Remember how she mentioned the rotation increasing the vulnerability? We think this is caused by the blades outrunning the corona space charge that dampens the electric field on stationary objects.
As an aside, I saw a dashcam video of a carbon fiber highway-scale lamp pole take a lightning strike. The biggest pieces coming off appeared to be about the size of a baseball bat.
No disrespect meant, but if I heard correctly you defined specific energy incorrectly. Specific energy is energy per unit mass; electric power is the rate at which electric energy is provided or transferred, (or, the rate at which work is done). No?
The truth is wind and solar are no where near as recyclable as a dam Or Have a life span like it. But pump hydro cost 40% more power to lift the water than is returned as it falls to the turbine so the outcome is the power bill rises20-25%
I would love to learn more about static dissipation systems for wind turbines. I assume, without measures to deal with it, they would build up a charge just like an airplane.
Step down the voltage, into usable amperage ranges, then store it in mechanical batteries, then push the mechanical energy generated by the mechanical batteries, into normal batteries. The energy can be pushed into water, to heat it up, and generate steam. Steam can power mechanical batteries. Ect.. Ect...
Lightening is green energy. We should consider capturing it on capacitors and putting it on the grid. The same strategy would work with triboelectric charges from the wind.
I wanna know why we are not using Lightning as a power source If we got, like, ten or twenty bolts of lightning, we have a potential to power the united states for 20 year if we did it right.
Hi Rosie, thank you for your informative videos. I find it hard to understand why the authorities insist on using horizontal axis turbines instead of vertical axis turbines.
Your answer as to why American wind turbines got hit by lightning and damaged is also why the US is anti turbines, citing the flaming turbines as the reason, not their own stupidity. They probably forgot that lightning is, more often than not, accompanied by rain, a very good conductor of electricity and also a reducer of resistance. I used to work in 400Kv substations doing repairs and installations and on dry days it was ok, the hairs on your boy would stand on end but there was little else going on. On rain days, on the otherhand, when working on a cherry-picker, it was earthed, every time it went within 50mm of anything metal there would be a discharge and if you had to touch anything metal you had to slap it to ensure a quick discharge. You said it happens more often than it doesn't, is this to do with the movement of the blade tip through the air building up a charge and attracting lightning? Would a metal mesh on the outside of the tip discharge to the LPS?
Lightning is definitely a pain point for wind turbine proponents at the moment. We will find a solution. The movement of the blade through the air does build a charge but most of the charge around a blade is due to a nearby thunderstorm. Metal meshes are used on some blades today but they have had marginal success.
Rosie, not related to this video but the heat dome over cities in northern hemisphere right now, figured you were the one person in the RU-vidverse to ask; Could a 'fan' blast air up from the highest point in a city, and tilted downwind or toward wasteland, not sure what angle, to bring in air from the surrounding area, with enough force to break the heat dome? How much energy would such a prototype use, and how efficient could it be hypothetically built if it works thermally? Seems the fan shape would not be a standard windmill, as the purpose would be a narrow jet to blast as far as possible, and the noise tolerance would be near zero. Would it have to be put on flight maps as a no-go zone? Instead of running several hours a day, it may be optimal to run periodically per real time data, allowing as little as a single air exchange per cycle.
The amount of energy needed for such a thing would outweigh any benefit by orders of magnitude. That's not even considering the capital costs of designing and building such a system.
