Wind Farms In The Night: On-Demand Warning Lights Are Coming

There appears to be no shortage of reasons to hate on wind farms. That’s especially the case if you live close by one, and as studies have shown, their general acceptance indeed grows with their distance. Whatever your favorite flavor of renewable energy might be, that’s at least something it has in common with nuclear or fossil power plants: not in my back yard. The difference is of course that it requires a lot more wind turbines to achieve the same output, therefore affecting a lot more back yards in total — in constantly increasing numbers globally.

Personally, as someone who encounters them occasionally from the distance, I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes. They can add a futuristic vibe to some otherwise boring flatlands. In other words, I can not judge the claims actual residents have on their impact on humans or the environment. So let’s leave opinions and emotions out of it and look at the facts and tech of one issue in particular: light pollution.

This might not be the first issue that comes to mind when thinking about wind farms. But wind turbines are tall enough to require warning lights for air traffic safety, and can be seen for miles, blinking away in the night sky. From a pure efficiency standpoint, this doesn’t seem reasonable, considering how often an aircraft is actually passing by on average. Most of the time, those lights simply blink for nothing, lighting up the countryside. Can we change this?

Light On Demand

Map of wind farm locations in Europe with heavy concentration visible in Germany
Wind farms locations across Europe as reported in the Wind Power database (Source: SETIS)

Improving warning lights to light up only when there’s an actual aircraft to warn in its vicinity isn’t a new idea, and individual tests to achieve this have been successfully carried out in the past. Looking at the map of wind farms in Europe, it’s not too surprising that Germany is especially interested in this subject, and is now implementing new regulations to enforce an on-demand warning light system as requirement for wind farms, expected to come into affect this summer.

Generally speaking, there are two options to know about an object in the sky within a wind turbine’s surroundings:

  1. the turbine is looking for an aircraft in the sky
  2. the aircraft reports its presence to the turbine

Established technologies exist for both options in form of radar and transponder signals respectively.


To simplify the basic concept of radar: radio waves are emitted into the wild, and if there is anything in their way, they bounce back to be received again, making it possible to determine the presence and distance of an object. Repeat it in a constant manner, and that object’s angle and velocity can be determined as well.

Like anything else in technology, radar systems have vastly improved and changed over time, and using Active Electronically Scanned Array (AESA) antennas nowadays, they can not only track multiple objects at once, but also look a lot more subtle than they used to. Instead of huge antennas rotating around, causing potentially new problems with the public, the radio wave angles are directed electronically, allowing the whole system to be fully stationary and placed into an inconspicuous looking box. Paint it like a cow, and no one might even notice it at all.

Transponder Signals

It would be even less conspicuous if we moved the responsibility to the aircraft itself, namely using ADS-B signals. ADS-B is often considered as a replacement for radar itself in air traffic control, and essentially consists of a transponder located within the aircraft that is periodically sending the aircraft’s identity, position, and altitude as radio signals for everyone to receive.

Of course, if a Raspberry Pi or ESP32 at home can receive the signals and make sense of the data, so can a wind farm.

The Catch

So far so good in theory, but as usual, in practice it isn’t that straightforward. A sophisticated system like an active phased array radar has a price tag, and the whole point here was to encourage more wind power adoption. Costs aside, if there is any disturbance with the radar signal causing it to become unreliable, the whole system would have to be bypassed, turning the lights fully back on anyway.

ADS-B would have significantly lower costs, however there are other concerns and issues with that approach, aside from possible satellite navigation reliability concerns. While large commercial airplanes are mostly regulated to require ADS-B transponders, it’s not necessarily the case for the smaller ones. And of course, not everything that flies has to be an airplane to begin with, and neither would it necessarily be of civil use. As ADS-B allows the tracking of an aircraft, some of them might not want to have that option, and others maybe shouldn’t have that option. In worst case, the system won’t be able to detect the very object that would actually need the warning lights.

Ignoring the details of which technology would be used, another aspect to consider is the interoperability with the wind turbines themselves, and the grown complexity of such a system as well as the security implications following it. Once the lights are triggered by an external event, and that event needs to be distributed to multiple turbines, things can go wrong in a lot of places, and the general reliability of such a system would be questionable. Plus, it wouldn’t take a take a hardcore conspiracy theorist to think about the consequences of such a system maliciously malfunctioning one day.

The Bigger Issue

But let’s take a step back and look at the initial problem itself: warnings lights are brightening up the night sky in order to inform pilots that a tall construction is present. To me, it sparks the question “why?”. Why do we fully rely on humans to handle air traffic safety here?

This isn’t even a question about your stance on renewable energy or light pollution, but why is there a necessity to shine a light at all as warning — regardless if it’s continually or on-demand, or whether we are talking about wind turbines, radio towers or just any tall enough construction. Installing on-demand warning light systems surely makes sense from an efficiency point of view, and I guess you have to start in some place, so why not wind turbines, but shouldn’t we rather focus on a whole new warning system altogether?

Take ship navigation for comparison: for centuries the lighthouse was the essential system to aid ships to safe harbor and avoid collisions on rocks and cliffs. And yes, they are still around today, with a surprising percentage of them even shining into the sea, but for the most part, newer navigation systems have replaced them for most of the parts. Yet, provocatively stated, air safety regulations are one step short of hiring plane spotters to manually turn the warning lights on. Ships have detailed maps of the ocean floor. Why don’t airplanes have the same for the ground?

We will see what the future brings, maybe our grandchildren will shake their heads in disbelief how we used to place all this responsibility in a few human hands without any concerns. Until then, we can look forward to a slightly darker night sky in the countryside again, at least in some parts of the world. Whether all this is really happening in the name of promoting renewable energy sources remains to be seen.

(Banner image by Jeswin Thomas)

117 thoughts on “Wind Farms In The Night: On-Demand Warning Lights Are Coming

  1. A combination of active and passive technologies might make the most sense here: Maybe a “light on demand” beacon on the tip of the blade, then a stripe of phosphorescent or radioluminescent material inboard of that, and then finally a stripe of retroreflective material, plus concentric rings of of the same on the hub/gear housing.

    Optical and audio aircraft recognition could be used as a backup for ADS-B input for the light-on-demand system.

    1. Um.. I would advocate against radio-luminescent paint on the scale of a giant turbine blade known to be difficult to recycle. A watch face is reasonable; turbines are not.

      There is already a minimum safe altitude (MSA) posted on aviation charts as well as a tower symbol and max altitude for anything of significant height. GPS-based electronic chart apps have the same data.

      Lights on towers are really a measure of last resort. They’re not for commercial aircraft which stick to controlled airspace well above the area’s MSA. Tower lights are more for general aviation (GA), ultralights, or light sport aircraft (LSA), and then most useful in emergency situations when the pilot is lost or has an emergency such that they cannot maintain altitude.

      ADS-B is a decent solution, but depends on aircraft having functional ADS-B transponders. Those will already be present in all aircraft in controlled airspace, which is not where turbines are found. Some of the aircraft that operate close to the ground, where turbines would be found, aren’t required to have ADS-B.

      Pilots are generally a smart lot, but occasionally you’ll find one flying drugs at night with no lights and no transponder. It’s easy to argue they would deserve a close encounter with a turbine, but the damage they would cause wouldn’t be only to themselves.

      Personally, I think wind turbines are an eyesore with our without lights. Solar is the only way to go.

      1. I should add that towers work as navigation aids when you’re following a sectional map from the air. Pilots can use their lights to follow their progress while flying a route. I know I have during my night flights. They’re highly visible from a long distance due to those lights.

        Removing them would also be removing one more manual navigation aid, making us ever more reliant on GPS. That being a technology that has been shown to be susceptible to spoofing and jamming… and also the technology ADS-B uses to know what coordinates to transmit.

          1. Odor? What about a wind turbine smells?

            I’m not being sarcastic; I really would like to know.

            (mods: sorry; clicked the wrong link on the comment below)

      2. I love solar too but the gracefulness of wind turbines is unparalleled, leaping in the sky like beautiful ballerinas. Most normal people love the looks of wind turbines however I recognize some have visceral neurotic reactions. An arachnophobic woman in Buffalo saw them as giant spiders. For the phobics wind turbines are eyesores. So I concede a few fail to experience their aerodynamic elegant beauty. Up to 97% of the people in a pole found wind turbines very attractive, somewhat attractive, or were neutral.

        1. Bro! Wind turbines are awesome i love their slow graceful move with long towers reaching for sky.In my back yard yes please, sadly i can’t buld one for my own because laws i cano only put up movable one (no concrete base) those are eyesores with short small blades whirling fast ughhh.

  2. Why would aircraft be flying at or below the altitude of wind farms? Commercial aircraft follow specific routes and approaches to airports to avoid ground obstacles. Small aircraft might fly in wind farm vicinity during the day but shouldn’t be at those altitudes after dark. This looks like a solution looking for a problem.

      1. Regulations can always change.
        A discussion about solutions to a current problem shouldn’t be stopped by stating the status quo.

        Is there really a need for everything above 200ft tall to have a beacon on it?

        A radiomast out in the middle of nowhere. Yes, a beacon here would be logical.

        A large wind farm on the other hand has no real reason to have beacons on all of its turbines. Aircraft should have knowledge of the farm’s existence along their planed route, and take it into consideration.

        If there is an emergency, then it wouldn’t be unreasonable to state that beacons would be beneficial.
        Though, is it truly a good solution to just toss a beacon on them?

        1. They say regulations like this are written in blood, so it’s might be best to maintain that, for the benefit of anyone who has to make emergency landings or such.

          Really, we just need batteries that use some common material like magnesium instead of lithium, and PV solar everywhere. Everything else has moving parts and huge structures and creates some kind of nuisance or another.

          For now the beacons are fine though, I suppose.

    1. There are times where aircraft fly low. For example, in an emergency, seeking a place to set down. In many regions, there are “airports” all over. Private strips and small commercial strips are much more common that many people realize, and, in the US at least, many farms will have one (or more). These are private, but registered and mapped. Obstructions, such as wind turbines, may not be properly charted, even months or years after erection (sad, but true), outdated charts get used, and, in an emergency, such details may be missed.

      There are plenty of other circumstances, but this is off the top of my head

    2. Considering just the light pollution issue, I’m not sure any sort of on-demand lighting would really be helpful. It seems to me it might be more disruptive to have the lights turning on and off unpredictably than simply blinking periodically.

      Also, how big a response radius would the lights have? Some areas see a lot of air traffic… The lights might be on almost all the time anyway!

      1. The photo of the lights reflecting off local haze or clouds brought up an interesting idea. There’s no reason the beacons have to be a fixed brightness. When they’re enveloped in visible vapor, they can be dimmed and still be very effective, as the vapor itself becomes part of the warning light.

        I would also like to see fixed hazards like these have their own ADS-B transmitters. For devices with ADS-B IN, the towers would show up on their flight display just like an airplane on a collision course, sure to get the pilot’s immediate attention. The cost would be low, and would work for both IMC and VMC.

        1. It turns out the FAA messed up in the design of ADS-B and there is nowhere near enough bandwidth to be able to use it for ground identification purposes. In fact, there is apparently barely enough to use it on all aircraft, but that has been just ignored. Better, it has no anti-spoofing capacity, so anyone can pretend to be an airplane and only specifically tracking down the transmitter can stop it. This is why ADS-B is not being proposed for drone/model aircraft. Instead the FAA is requiring a live internet connection to handle the data. That will also make it illegal to operate a model or drone where an internet connection is not available. Gotta love the FAA.

    3. Helicopters are also aircraft and do generally land at low places. I could for example imagine an emergency medical helicopter getting in a dangerous situation when picking someone up from a rural location in the middle of the night.

  3. Why not turn the argument around. Why not put the radar into the airplane? Might also help with not flying against mountains in the night as sometimes happens as well. The windmills are not going anywhere and should not be the ones warning airplanes, with the light polution and problems it causes. Airplanes, solve your own problems.

    1. We already make tremendous concessions to airplanes, every urban airport is chewing up hundreds of acres of prime real estate.

      When you consider how powerful a plane-based radar would have to be, in order to be effective, do you really want to blow away every wifi and every police radio when a plane flies overhead? Talk about creating problems.

      1. Really? How powerful *would* a plane-based radio (radar) signal need to be? Is it reasonable to believe those few milliwatts at a radically out-of-band frequency would have any effect at all on other radio services? Baseless FUD.

        1. Kilowatts: 5-10 kW for a typical surveillance radar system.

          A milliWatt level doppler radar can barely see 30 ft ahead, and already these radars operating at 2.4 GHz, 10 GHz, or 24 GHz are tightly regulated because they interfere with military and emergency services bands.

          1. Radar in a plane to look for ground targets is useless due to clutter (SAR imaging notwithstanding). Ergo, the sole purpose of a dedicated plane-mounted transmitter in this context would be to trigger the tower lights or some other beacon (like a transponder): it would require a receiver on each tower. The plane need not transmit more than a few milliwatts for this to work.

            There is already radar on most commercial planes anyway. I’m admittedly out of date, but I’d still wager a conventional radar won’t reliably distinguish a turbine from other clutter.

        2. The ADS-B transponder itself has already up to 1kW of peak (pulse) power. And that does not rely on reflected signal ike a typical primary radar. The airport radar sends a pulse and the transponder receives and answers it with a coded chain of pulses.

      2. It would only require corner-cube reflectors to be added to the towers to boost the return signal incredibly high over the typical return – like factors of 100 to 1000. If a tiny one on the Moon can return a low-power pulse to Earth, a 6 footer on a tower will be visible to weather radar from 30 miles or more. if made not-omnidirectional and set to spin, it will blink on and off. Examples – kite fliers put small reflectors onto kite tails near a military base and were soon talking with people looking for an airplane or helicopter that seemed to be hovering in the area. And that’s well into the ground clutter region.

        1. A lot of angles of a truck box also happen to be excellent corner reflectors, so just need a parking lot in the same line of sight and which bright blob is the important bright blob.

  4. “but for the most part, newer navigation systems have replaced them for most of the parts”

    What about the parts that don’t have some of the parts in their parts, even though parts of them have most of the parts in their parts?

  5. So you’re flying along, have an engine failure in a single engine aircraft. Looking below you see a large dark field, gliding hoping to make a smooth landing. You are committed to the field when suddenly an acre of warning lights turn on. Now you have to slalom around spinning turbines. Going to get to the ground before getting whacked by a blade.

    Leave the lights on.

    1. I suppose – though a large dark forest filled with trees looks the same as does a lake, especially with cloud cover and no moon. This is why a divert map should be maintained the whole way by pre-planning the IFR trip.

  6. I myself is of the opinion that it should primarily be the airplanes responsibility to not crash into stationary structures.
    Be it mountains, skyscrapers, or wind farms. Beacons shouldn’t be needed. VFR isn’t something one should fly by during night in unfamiliar areas regardless.

    If it is a large, “permanent” structure, then the airplane pilot should have taken it into consideration before even considering flying the plane. (This is though already part of standard procedure for flying a plane.)

    If there is a wind farm along one’s planned route, then one’s maps will already show that. Though, having looked at air plane maps myself, they are a cluttered mess to be fair… They do contain tons of valuable information, but few “general warnings”, so have fun sorting the frankly trivia level facts from the more important dangers.

    Would be nice with a map that just grades stuff depending on how much caution one needs to take in regards to it.
    A simple scale. Then just draw areas on the map around each such object.

    For an example, a radio mast could be marked with a large red circle, and a number for stating how high it is.
    Same type of marker can be used for a wind farm, sky scrapers, or a mountain. Its simply a tall thing that a plane needs to avoid. (The marker should preferably be clear enough to be easy to see on a paper map. A digital map where one plans the route can on the other hand just make a long list of everything along/near one’s route.)

    1. I myself is of the opinion that it should primarily be the boaters responsibility to not crash into stationary structures. Buoys with flashing lights are expensive and outdated. Boats are required by law to carry detailed maps of the floor so the buoys are unnecessary anyways. Same with chanel markers and the like, just put a green and red line on the map and you’re good.

      1. Seems like there’s nothing modern hacker types like more that to push even more responsibility onto human operators.

        It’s almost like those people who think we shouldn’t have electric lighting at all. Tech people love coding, they love hacking, they love math and logic and puzzles, but they don’t seem to like tech itself all that much.

        Sure some will go for home automation gadgets and such, but many think it’s too insecure to even have a printer on the WiFi, and that there’s really no need for backup GUIs, you should just “Be real careful with dd”.

    2. Aviation is about mitigating risks with as many redundant measures as possible. Yes maps contain these. NOTAMs contain temporary objects. Pilots are supposed to check them and usually do.

      Still, bad things happen. A pilot could get lost, have an emergency electrical outage, think no GPS. That’s where the lights come in. And the ‘smart’ turning on wouldn’t work then either, this is probably why this isn’t done already.

      Anyway, those lights are a relatively low power drain. Not even worth worrying about.

  7. Because flying at night is still a legal thing to do as long as Visual Flight Rules are followed. Flashing lights on the tops of tall things are printed on charts, and are used as aids for VFR navigation. There is no requirement for general aviation aircraft to have GPS or other electronic navigation system; as a matter of fact there are a lot of small planes flying that don’t even have electrical systems at all – they hand-spin start their engines, and their dashboards are completely mechanical gauges. (For night flying, they’ll have battery-powered marker lights installed.)

    Instrument Flight Rules don’t require tall blinky things to advertise themselves, but they do require a whole lot of expensive electronic equipment, and special training for pilots. Today, IFR isn’t required for night flying.

    Might GPS change this? Probably not. Aviation is kept safe due to redundancy, and GPS is not guaranteed reliable enough in every possible condition (consider the GPS spoofing happening on the oceans today causing ships to collide.) So how does a plane safely navigate and land when GPS goes down? The pilot looks out the window, and compares it to what he or she sees on the charts. The FAA would have to change the rules to require IFR for night flying, but that would be an extremely politically unpopular move.

    1. Up until 2012 in the UK only pilots using IFR were allowed to fly at night.
      Since then we’ve adopted the European-wide regulations which do allow some VFR at night, but with more restrictions than daytime flying:

      * Minimum cloud ceiling of 1500 ft AMSL
      * Flight visibility of 5 km, or 3 km in the case of a helicopter flying outside controlled airspace
      * Maintain sight of the surface when flying at 3,000 ft AMSL or below
      * Minimum height of 1000 ft (or 2000 ft if over high terrain) above the highest fixed obstacle within 8 km of the aircraft except when taking off or landing

      That last one means that if there’s a 300m radio mast anywhere near your route, then your minimum altitude is going to be at least 2000 ft.

    2. Here’s a controversial opinion: aviators rule of the sky needs to be ended.

      They successfully lobbied to take down drones and keep their walled garden but they refuse to integrate new technology and improve safety to the detriment of all the other industries.

      For airplanes:
      GPS should be mandatory
      3D terrain apps like the Garmin Head-up Display should be mandatory
      Night vision cameras should be mandatory

      They only cost a few hundred dollars.

      Oh your plane doesn’t even have electrics? Add some for the safety equipment or you’re grounded. No discussion.

      Kobe died because of this asinine attitude of aviators. Any of those 3 safety technologies would have prevented his crash.

      Digitize the skies. Allow drones back. Hotshot renegade pilots need to remain in the previous century.

  8. I’m sorry, but turning off warning flashers because they waste power is just silly. The power “wasted” in warning away aircraft is tiny fraction of a percent of the power wasted in lighting up lightly traveled roads. If you really want to save some power, make those lights sensitive to traffic. Leave the warning lights as they are.

  9. One pretty cheap solution: Equip every turbine tower with an airband receiver tuned to (say) 123.45 MHz (*). If the tower hears any activity on that frequency then turn on the lights. Any pilot can summon lights on demand using their ordinary radio, or even have a beacon pinging on that frequency every mile or so.

    I’d heard of this method being used for runway lights when I flew in the 80’s, so it’s not exactly a novel idea.

    (*) the air-air common channel, not used by any air traffic control towers. Maybe not the best to use in some areas.

    1. This sounds like the best solution so far, or is there any hidden problem I’m not seeing?
      Occam’s razor states that the simplest solution is usually the one, and this seems easy to implement

    1. Unfortunately, it’s going to take hundreds of thousands of acres of windmills to replace fossil fuel burning generator plants. But, I’m sure that we will get to a point, where we realize just how ridiculous the idea was. Probably come in about 15 years, when many of those windmills start to fail. I feel confident that the ‘green’ dream will lose popularity, when people are expected to actually start paying for all this stuff.

          1. Nope, those turbines require lots of maintenance. Not to mention the wind at the Tehachapi wind farm is intermittent as can be.

            And if the wind is too great they have to shut down the turbine.

            BTW the company that maintains them are always hiring techs because the work is nasty and dangerous.

            Basically that wind farm is one giant white elephant and all around eye sore.

      1. +1 I have nothing really against the IDEA myself and have always wanted to build a small one, but working at a place where I sometimes (often) had to reset the controls, and a couple times climb up to the nacelle and untangle comm lines because the turning motors got “lost” and wound up the cables cured me of that. It died at about 15 years old and repairs unavailable as it is ”obsolete”. I really ticked off the owner asking if it would truly make up for the CO2 released in making the 150 cu yards of concrete in the base with tons of re-rod, the 100 or so tons of steel tubing in the tower, not to mention the copper,steel, and plastic at the top.
        In 3 years I never saw it reach 20% of it’s advertised rating, had to double check the instrumentation I installed to report data to a web site, thought I made a big mistake somewhere but no!….Hope they’re better now…

      2. Ridiculous how? Of course, wind machines need repairs and maintenance, and will eventually need to be replaced. Hey, here’s an idea- how about instead of sending someone down into a hole to dig filth out of the ground so we can put it into the sky and into our food and water, we train that guy (or his kids who don’t yet have black lung or silicosis) to install, maintain, and repair wind machines?

        The cost of maintenance and replacement is taken into account when calculations are made to decide wind vs coal vs solar vs hydro vs geothermal. What hasn’t been taken into account historically is the real cost of burning coal that includes the cost of poisoning the air, water, and food supplies.

        1. It’s called baseline energy. Wind is intermittent and cannot be used to generate baseline power to say run a city or heavy industry – you know like the factories that smelt the ores that are turned into magnetic alloys used in the turbines .

          Merkel found that out when she shut down her nuke plants and then became dependent on Russian oil and NG to keep her country from collapsing.

          Right now there is no substitute for either NG/Coal/Nuke power plants for generating baseline energy.

          BTW our love of cell phones/Ipods and other portable devices causes a lot of pollution. In China or Africa slaves or children are used to extract those metals needed to make batteries and the ores are refined in nasty, polluting smelters and foundries in a country with no environmental laws. Just so you have your cool portable electronic toy.

  10. Aircraft are not required to have ADS-B in Class D ->G airspace, so you may be legally navigating your Bugsmasher 9000 some night, lose an engine along with any electrical system (yes, you can legally fly an aircraft without any electrical system, but you’ll need at least battery lighting to do it at night) and wind up in the world’s biggest Cuisinart.

    I fly near windfarms and they’re beautiful, but the thought of a deadstick landing among them even in daylight is terrifying. Also the lights are only on the towers – they don’t indicate where the blades are, though in a perfect armchair-quarterback world you could calculated it from reported wind direction if it’s the same one the turbines are “seeing”. Maybe.

    Sorry if it spoils the scenery. Enjoy the megawatts in the meantime.

  11. This seems pretty simple to me – police and ambulances have had for years the capability to turn all the traffic lights red by flashing visible light at a specific frequency – why not just implement the same with airplane lights? The headlight could pulse at 70Hz and the tower/obstruction could be tuned to respond.

  12. I live a county south of one of the biggest wind farms in the world. You can’t look anywhere and not see that in sync blink everywhere in the next county north of here. Purdue has had an airport long before Amelia Earhart took off in one of their own planes. It’s essentially on the edge of the big campus. Now the skyline across the river valley form me is dotted with red lights on all the time on buildings that have been around much longer than the latest air directive. There are training flights going on all day till after dark over the greater town area going round and round.

    I am reminded of that scene in the Jetsons when George swoops down for some reason and startles a bird walking on the ground and the bird remarks that even the ground ain’t safe anymore. Between outdoor cats and wind turbines, birds are on the decline. Blinking is at least better for birds than continuously lit towers. Texture patterns show some use here unlit.

  13. “Hate! wind farms. Not “hate on”. I’m not even good enough a student of English to tell you exactly why and how wrong that is. Mind, I’m not paid to be a journalist, so perhaps that’s some sort of excuse.

  14. or just build more nukes? I mean, ~56 reactors would entirely replace the peak output of all the wind farms in germany…and it would be nice, steady power. and only 56 blinkenlights to worry about :P

    1. The peak output of wind farms is a nuisance on the power grid because you meet the energy demand by the averages, not by the peaks. The actual power output is 1/3 – 1/4 of that, so about 14-18 reactors. Off-shore turbines are better, but they’re also 10 times more expensive.

      As many as Germany is now shutting down.

      1. To elaborate: the issue is that the power demand over a typical day varies by a factor of 0.4 while the output of wind power varies by a factor of 30 for an individual turbine, and by a factor of 5 for a whole country full of them. A UK study concluded that wind power can be relied on only for 3% of its installed nameplate capacity.

        When the peak comes, the power utility finds it difficult to find any customers to buy it. The power is largely exported to the larger European Synchronous Grid with over 500 million consumers to dilute Germany’s renewable power down. Other countries are kinda pissed off about it since they’re having to deal with large power fluctuations and the probability of another continent-wide cascading blackout like in 2006. Switzerland for example has installed phase shifting transformers along its borders to control the flow and stop German wind/solar power from pushing through its grid when they don’t want it.

        1. Yeah. We’ve had good examples here … When we ‘really’ needed power, solar and wind wasn’t there across the state ( I work for a utility). We had some very cold nights. No wind. No solar. Good thing we had nice steady power from coal fired plants to help handle the load. On cloudy/stormy days… reduced or no solar. Even hydro is down in the winter as not as much water is flowing. Need some nice Nuke facilities to really have some clean steady energy. People in our current ‘information age’ want no power interruptions, yet they want wind and solar which are really opposite of their ‘want’. Not to mention wind and solar aren’t as predictable and are harder to ‘control’ on the grid. Take up a lot of land mass too. Besides being an eyesore (solar and wind). You can’t just increase power with solar/wind plants to meet demand on the fly like you can hydro or coal, or gas fired, etc. Remember in an electric system demand must always equal (not more/not less) the supply or bad things can happen.

          I wonder if any studies have been done on man made climate change when you are removing ‘power’ from the wind (not to mention the birds that they kill). Also with solar panels absorbing power instead of the ground or reflected back through the atmosphere as it normally would. We probably don’t have enough evidence yet.

        2. 3% of its installed capacity? Germany got 35% of its power from wind in 2019. If the return were 3%, then that would mean that Germany bought 10x the wind-wheels it required for its entire power budget? Those numbers don’t make sense together.

          I would think that if anywhere in the world could handle nuclear safely, it’s Germany. Technical competence combined with stable plate tectonics… But the scars from Chernobyl, where you couldn’t eat veggies or drink milk, do kind of loom large. I don’t judge.

          The UK has done very well with its move to (largely offshore) wind power. Better and faster than Germany, from a reduction-in-coal perspective anyway.

          Switzerland puts up walls so that the wind from Germany doesn’t blow in. Switzerland is, no offense to our Swiss readers, its own thing.

          1. It means you can expect a minimum of 3% of wind power to actually be on line – that’s the bottom line caused by “it’s always windy somewhere”. It’s true, but it doesn’t say how windy.

            At least half of the output happens during the production peaks, which means most of the time the wind turbines in an entire country are producing less than the average. Not always 3% little. The actual median production is around 20% of the nameplate capacity. This number is higher than typical because Germany has installed a lot of off-shore farms recently and those work a little more consistently.

            With a 5:1 relationship to peak vs. median production, and Germany producing 35% of its power from wind, they have a peak capacity around 1.75 times their average grid demand. This is somewhat mitigated by the fact that the best wind power season is in the winter, so the present wind power capacity is very close to the seasonal demand.

            However, you can’t just switch the entire grid over to wind power because you can’t just turn all the other power plants off, even if by German law wind power has the right-of-way on the grid. That’s why Germany is simultaneously a net exporter and facing power shortages from the closure of nuclear plants.

          2. >But the scars from Chernobyl

            It’s not so much a scar than a scab people keep rubbing off to prevent it from healing. Nuclear power is a solution that doesn’t involve social control/engineering and state regulation of consumer habits because it’s plentiful and cheap – it’s business as usual without any need to change the social conditions – so the political left naturally doesn’t like it, and they’ve co-opted the greens in the same hate despite an obvious conflict of interest between the political and the environmental ends. Inciting anti-nuclear hysteria, many times by outright lies, is simply a blunt propaganda instrument to steer people into voting for the left.

            The left likes wind/solar power because it has many issues which “require” social engineering and big state as (partial) solutions. Energy rationing, never-ending taxes and subsidies, state control of the power market… etc. They have been riding the anti-nuclear platform for decades also because nuclear power conceptually represents heavy industry and capitalism – the “hard values” of the right; Angela Merkel’s party.

            Merkel grabbed the proverbial spear and turned it around by appealing to that very sentiment. Her coalition was suffering a 36% approval rating through 2011 and playing into the Fukushima crisis was a great PR boost on the campaign. By the turn of the year 2012 her approval rating had shot up to 77%.

          3. Ps. Watch left/green people complain about nuclear waste, then watch the same people complain about any and all nuclear waste disposal propositions and block/protest them everywhere.

            You’d think they’d be happy about finally putting the waste away – but that’s not the point. As long as the waste is around, you can complain about it. If it’s gone, there’s nothing to complain about, so there’s a danger that nuclear power becomes acceptable again. Therefore, the nuclear waste situation cannot actually be resolved – these people need it for political purposes. It’s sort-of similar to fire fighters who turn arsonists in order to appear as heroes.

  15. I’m sorry. but I don’t understand why, having the lights on all the time during the dark hours is an issue.. That is a tried and trued operation for decade on broadcast, and communication towers for decades. No doubt the most recent navigation charts have the total height of a wind turbine field. Why add complexity that have multiple failure points? Nowhere in the write up was it mention the current methods ar causing a accidents. I suspect the force of this is about some of the entitled beothing, about something don’t have to look The lights of s small city 24 miles distant in pollutes to horizon to my south, not the warning light at wind field that’s 15 miles closer, so ther is no way the warning lights are “lighting up the countryside” A somewhat technical somewhat of a forum shouldn’t be using hyperbole.

  16. Well an unbiased introduction of course: “There appears to be no shortage of reasons to hate on wind farms.”

    Well try to love them, much, clean and cheap energy and they can really deliver huge amounts of energy – saving your life style in spite of a climate crisis.

    “I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes.”

    Yeah and you ignore the scenic non-industrial roads and highways that brought you there so you could enjoy the mountains and hate the wind turbines, not traveling by plane wagon with your horses, but by your gas guzzling machine, roaring softly through that beautiful nature – which you can’t hear – but the outside nature can – because the inside of your SUV has a nice sound insulation.

    “They can add a futuristic vibe to some otherwise boring flatlands.”

    Well, in contrast to that it’s funny when my german compatriats complain about them being an “eyesore” to the natural beauty of the landscape, consisting of “industrial-scale” aggricultural flatlands, being topped in biological diversity by every aquarium.

    1. > and they can really deliver huge amounts of energy

      It’s a moot point when wind turbines are completely dependent on fossil fuels and electricity imports to even operate on the grid – everybody has to bend backwards to accommodate them on the grids and at best they can provide a small fraction of the power while making the rest of the grid totally dependent on burning natural gas for load following turbines.

      Every megawatt of wind turbines needs almost the same number of backup power, which ends up running 70% of the time for most of the actual energy demand.

      1. Not to mention all that distributed and dispersed generation capacity requires a huge amount of grid infrastructure, and it must be sized to accommodate the peak output those fickle sources will produce.

      2. We should probably be scaling loads to meet supply rather than the other way around, now that so many processes are automated, and electric heating is common (Which can use phase change materials to store heat).

        Isn’t natural gas itself fairly clean compared to what we used to have?

        1. Thermal energy is easy to store in large amounts, but it’s really low value. Just burning natural gas is about five or six times cheaper than using wind power for the same purpose, and electricity in Germany is very expensive anyhow – so people naturally don’t like to heat with electricity. The majority of domestic heating and cooking energy in western Europe and the UK comes from natural gas and fuel oil, whereas eastern European countries like to use district heating plants for hot water and space heating – often burning Russian coal which comes in at only 1-2 cents a kilowatt-hour.

          1. And, these days you can improve the cost efficiency of even gas-fired heating systems by installing an absorption air-to-air or ground-to-air heat pump. They run on natural gas or propane and can provide both heating and cooling, so there’s no advantage in using electricity in countries where the subsidies and surcharges have driven the power prices to ridiculous levels.

            The irony is that renewable energy is winning the electricity sector because it’s driving consumers out of it. The advocates interpret the reduced electricity demand as improved efficiency, when in reality both consumers and the industry are slowly switching to other sources and generating their own energy from gas to avoid the instabilities of the grid.

  17. On a business trip last year I saw a LARGE turbine right on the waters edge in front of the Encore Boston Harbor hotel/casino. I believe its at the Mystic Generating Station near Charlestown, MA. Everybody wants free energy … in someone else frontyard! (Not one mention of birds ;)

    1. Famed teetotaler Ted Kennedy who never harmed a fly famously opposed the Cape Cod offshore wind project because it would be in his view.

      I find it curious that no one has exploited wind power as a source of free bird meat.

  18. Totally agree about the eye-sores. Especially in places like Easter Washington where wind farms have spoiled the vistas along the Columbia River: Wind farms required by progressive green energy policies because the hydro-power is not classified as green. The hydro on the Columbia makes surplus power and is the cheapest in the US. If the wind farms were demolished power would be cheaper and truly greener.

  19. Any reliable system for on-demand lighting would add incredible complexity which, IMHO, vastly exceeds the benefit.

    At least in the US, these warning lights are slow pulsing red lights and are only required to operate during the hours between sunset and sunrise, so they’re actually off most of the time anyway. Most of them, while they can be seen for miles are not particularly bright, even up close.

    To me, I really don’t see the big deal. Seems like a solution looking for a problem.

  20. I have studied Wind Farm Syndrome, Long Term Infrasounds Exposure Chronic Fatigue Syndrome on all continents for the last 50 years.

    Infrasounds generated by wind towers are transmitted through the ground many kilometers away and can be studied and detected by seismographs.

    Infrasounds generated by wind turbines match brain waves signatures, so can overclock or down clock your brain waves, making you 24//365 sick.

    The largest Wind Farm Syndrome study was conducted by the Senate of Australia.

    President Trump announced last year, that nobody should live close to a wind farm.

    If you are interested to learn more about brain waves, infrasounds, Wind Farm Syndrome, Chronic Fatigue Syndrome
    just email me one day

    hfexchange at gmail

    1. President Trump looked at the sun during an eclipse. The man is an idiot.

      The Australian Senate study was a delaying tactic, run by a known anti-renewable crackpot.

      Neither source are reliable.

      1. There’s a non-negligible correlation between the loudest opponents of wind farms, and those people whose properties are in the exclusion zone of a nearby wind farm and so can’t get paid for putting one up on their own land.

  21. Light ‘pollution’ a problem? We have invented these things called curtains, you shut them at night to drop the light coming in to your bedroom…

    I think the fundamental premises for this article is silly – who cares if there are lights on top of towers. It’s a hell of a lot less light than I get in the windows in a large city at night, and it doesn’t cause anyone actual problems..

  22. This. A great big wind generator should have no problems running a an intermittently-on red bulb, with a group 24 battery to run it when the wind don’t blow.

    In general, the proposed ideas are overkill, expensive, and less reliable, compared to a flasher with a photocell or timer.

    Various things could be done with the bulb, lens, colour, interval to make their ground-level visibility and light pollution less offensive, while maximizing visibility to air traffic.

  23. That map exaggerates the situation here in Germany. What is the diameter of one of the dots in the map? 30km? Of course, if you increase the size of the dots you will eventually cover every country.

    I don’t mind the wind turbines here and I don’t mind the dim red light on top.
    What I hate is the partially flickering flourescent lamp in the sign of the shop across the street.
    There should be a law against that.

    1. Ah once again the perpetually broken HaD comment engine fails again. The post above was in reply to @Pete says: March 24, 2020 at 3:28 pm above. The Reply button is broken HaD.

  24. Ships are slow, planes are fast and need to stay fast. If a ship’s navigation fails, you can stop the boat until you fix it. If a plane’s navigation fails, you got a limited amount of time to land safely, with instruments only, before you run out of fuel.

  25. I’m professional seaman and private pilot of ultra light plane . Light tower in Europe are all in function, shinning to the sea. Yes. And it will be like this for ever. This is one of the most important safety thing we have to make positioning possible in case of total blackout on the ship. That why, in every passage plan we prepare before a trip, we have the position and corresponding signal of all light tower we suppose to be able to see, bespite of having redondancy of electronics charts and gps/gnss on board. Just one time at sea, in blackout, with bad weather, and you will fight to keep light tower shinning for the rest of your life.
    I am encline to kill with my bare hands for that purpose and be sure, i’m not alone. Because that save lifes.
    For light on every windmill or structure over 200ft, it is the same. Ads-b should be mandatory in all airplanes, but, another time, in blackout, it will not work, without speaking that i’ve never seen something never fail.
    A radar is not capable to see my composite ultralight plane, that’s why airports ask me to have ads-b on board if i want to land there.

    It’s easy to speak when it’s not your life who rely on this.

    Some guys would better take care of all others polution before “light polution”, something you can fight with a CURTAIN, like said previously.

    I’m a silent lector of HaD since long time and never read a post like this. It’s more than just egoism and stupidity , it is just…. I’m not able to tell the exact words.

  26. Just like lighthouses have area sectors to block out light, why not just block out light visible from the ground? Unless you live on a mountain or a really high building you would not see the light.

    Or use polarized light so you need polarized eyewear or windshields to see the light.

      1. My parents were poor and couldn’t afford the polarized option. Couldn’t even afford the Grade A eyeballs. Forget about polarized — I got the factory defects that can only focus 20 cm away.

  27. The phased array radar might be a good choice, but then you’ve got military craft, at least in the USA, that appear to be much smaller than they actually are on radar, and they take off from the midwestern US, where an enormous number of wind farms are. I really doubt there would be any reason for the stealth craft to be swooping low over the plains, and being military aircraft, they likely have access to the best GPS and mapping technology in the country, not to mention their own radar systems on the plane, but some “cover my anus” politician will no doubt still necessitate it as part of the bill.

  28. “why is there a necessity to shine a light at all as warning”… Because when a plane is flying as low as the height of towers or even wind turbines, they use their vision… not instrumentation unless its for landing, then ILS comes into play. You can state your frustration all you want, but its not going to change anything.

  29. Hey — longtime former wind farm designer/operator here. Maybe best not to lead off with a wind farm study written by European Atomic Energy Community (Euratom). If anyone has a hate on for wind power, it would be the org responsible for maintaining the market for nuclear power in Europe.

    Turbine lighting has come a long way from the feeble, repair-heavy unsynched incandescent lights. LED lights have a short duration and are kept in sync using a GPS in each beacon. They’re also focused and shaped to prevent as much light hitting the ground nearby as possible. But they exist to be seen far away for safety, so you’ve got to let *some* light out. In most countries, lights are not required in every turbine, just those that would define the project boundaries.

    On-demand lights are an interesting problem. If pilots insist on the right to operate un-instrumented, beaconless vehicles able to cause loss of life and property damage on impact, there’s no magic sensor that can be installed to detect them in every case. Having a wind farm operator take full responsibility for air safety decisions is not something any regulator or operator wants. Both realize that they have a responsibility to maintain safety at the lowest impact to the community. So radar on turbines with airband radio broadcasts and lighting controls based on weather conditions can help in some projects. But they’re still no substitute for turbines being mapped on navigation charts and proper flight plans.

    Turbine blades already show up on ATC primary radar — as do road vehicles, buildings and migrating birds. Most ATCs have masking capabilities to block out known noise such as buildings and highways. Some ATCs are quite old, though, and their blocking store is a few KB with zones defined in EPROM. Turbine blades also produce a significant doppler return, so a single wind turbine blade may appear as a small unidentified aircraft taking off, climbing briefly, then immediately crashing. Multiply that by three blades per turbine and many turbines per farm, you get what I heard an ATC operator describe as a “CFIT Fest” …

    Putting transponders in turbines to generate an SSR return may also be unwelcome. There’s already the bandwidth issue, mentioned many times above. Regulators and ATC operators are not too keen on non-aircraft devices squawking. And no amount of transponder installation will help VFR pilots.

  30. Why dies it just have to be an annoying red light? Why not make them interesting and enjoyable? POV displays have been around for a decade or more, and windmills seem like a perfect place to use them. Even simple basic patterns would distract from the read beacon, we’d probably want to keep on. Some windmills could be fitted with some high resolution displays, for advertising, or public information. Seems like a possible revenue stream, if they could sell access over the internet, so pretty much anyone could upload a pattern or display, even animations. Wind power could be fun and entertaining, as well as supplement the coal and gas powered plants.

    Obviously, the electrical grid needs to be redesigned, to better accommodate wind and solar. We need something to smooth out and regulate production. No way to predict the output of wind and solar, just like there is no way to precisely predict demand. With demand, we have normal habits, and trends, that only occasionally change drastically. For wind and solar to be really useful, we need a storage solution, even if it’s short term. This would help deal with surplus surges, and fill in the gaps, when clouds pass, or the wind isn’t blowing so much.

    1. POV windmills would be an absolute visual nightmare spectacle. What they could do if safety allowed, is to cover them with realistic camo(Like RealTree) that matches the environment. A floating red beacon (I have no idea why it can’t be green instead, it’s more visible and common in nature) is a lot better than a whirling lightsaber.

      You could also make them look like old fashioned wooden farm windmills, or a vauge three bladed version thereof. Or, just put up actually old style windmills, because those might sometimes eork in places normal windmills just won’t be accepted at all.

      Artistic design is hard when there’s a phobia of any kind of imitation. Nobody wants to make things realistic, so we get these horrid stylized fake tree phone towers, and obnoxious loud patterns on everything when they try to do public art.

      If you got the artists who do the background design for Disney parks to do windmills they could be pretty awesome.

  31. I’ve talked to many property owners complaining about tower obstruction lighting… They often ask: “Why are the lights so bright to people on the ground, when they should be bright for airplanes”. Tower obstruction beacons are built as a last gasp attempt to avoid a collision with an aircraft that has already encountered multiple issues to be on a collision course. The accuracy of the lenses and reflectors don’t magically cut off at the horizon or ZERO degree’s. Some beacons, especially based on Fresnel lenses have side lobes that will send light down at the ground. Others have LED’s internally aimed downward at reflectors, which means that stray light can be visible to anyone standing nearby.

    The beacon manufacturers are partially at fault as they could do a better job to accurately cutting off downward light. But realize at a mile or kilometer away from a tower, the trigonometry demands incredible accuracy. Rolling terrain will also negate any ability to differentiate between the horizon and the ground.

    The required beacon output is based on “acquisition distance” with marginal VFR conditions. The pilot has to acquire the obstruction far enough away that they can still maneuver to avoid it. That means that during clear visibility conditions, the beacons are brighter than is necessary. A variation that has some hope is LIDS, ( a method to decrease beacon brightness during good visibility. Placing visibility sensors on a few of the towers in opposite corners of the wind farm and then acting on the worst case. Consistently clear conditions across all sensors can dim the beacons down to even 10%. A number of tower lighting vendors do have the ability in their controllers to dim their LED lights… the feature is not used. I did a test with one of my firm’s 400′ towers and found that going to 10 or 15% is necessary for the human observer to appreciate the dimmer output.

    Since most of the LED beacon systems are PWM anyway, why not simulate the rise and fall output characteristics of an incandescent bulb? Some folk suggest that would be less obtrusive than the step function now used by virtually all manufacturers.

    New Infra Red emitter requirements for towers could take a very different approach since IR is invisible to humans, truly obnoxious output patterns could have been defined. A continuous fast flash rate would show up quite nicely on Night Vision Goggles due to POV of the phosphorous light amplification tubes. But the regulator decision was for IR to duplicate the same output flash as visible light. How to differentiate various light sources when panning the horizon? They all look green!

    Have you seen new Catenary requirements? Quite a sequenced light show!

    While aviator safety, and liability for all parties are the highest concerns, the regulatory side doesn’t seem to have much drive to avoid light pollution for the ground based stakeholder.

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