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The Ever-Present Glow of LED Greenhouses
- mytailorisrich 7y agoThe Netherlands primarily fossil fuels to heat and light greenhouses. This industry has a large carbon footprint.
- itcrowd 7y agoJust to give some numbers: The Dutch greenhouse horticulture sector has emitted 6-8 megatons of CO2 per year between 2000-2015 and emissions are expected to decrease to ~4 megatons of CO2 per year in 2020 [1]. 7 megatons is approximately 4% of national emissions [2]. [1] pdf, https://www.wur.nl/upload_mm/c/e/c/f827af2c-9ae6-4bb5-bb47-920f4700cef8_2016-067%20Velden_rapport_def.pdf https://www.wur.nl/upload_mm/c/e/c/f827af2c-9ae6-4bb5-bb47-9... [2] https://www.cbs.nl/nl-nl/nieuws/2018/37/co2-uitstoot-in-2017-gelijk-aan-die-in-1990 https://www.cbs.nl/nl-nl/nieuws/2018/37/co2-uitstoot-in-2017...
- MuffinFlavored 7y ago> 7 megatons is approximately 4% of national emissions What makes up the bulk of national emissions?
- itcrowd 7y agoAs of 2nd quarter 2019 [1] rougly: 32% Energy, water and waste services 24.5% Agriculture, mining, industry, construction 12% Other services 13.5% Transport 18% Households This is a major challenge (not only in the Netherlands) because it appears there is no one "bulk emitter" that must be tackled. [1] https://www.cbs.nl/nl-nl/nieuws/2019/39/uitstoot-co2-hoger-in-het-tweede-kwartaal-van-2019 https://www.cbs.nl/nl-nl/nieuws/2019/39/uitstoot-co2-hoger-i...
- mytailorisrich 7y ago4% of national emissions is a lot considering the purpose here, and taking into account, as said, that the Netherlands emit quite a bit to begin with because of fossil fuels use (Wikipedia says they emitted twice as much as France per capita in 2014 [1], for example) [1] https://en.m.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita https://en.m.wikipedia.org/wiki/List_of_countries_by_carbon_...
- sxates 7y agoMaybe they should just pump that CO2 into the greenhouses!
- foofoo55 7y agoThey do. But more commonly, CO2 is intentionally produced in greenhouses by burning natural gas (or propane) for no other reason than to create CO2 for the benefit of the plants: https://dutchgreenhouses.com/technology/co2-enrichment https://dutchgreenhouses.com/technology/co2-enrichment
- socialdemocrat 7y agoSeems like this could have been better done in Iceland with access to lots of heat and power from renewable sources.
- zeckalpha 7y agoThey do: https://nea.is/geothermal/direct-utilization/greenhouses/ https://nea.is/geothermal/direct-utilization/greenhouses/
- NeedMoreTea 7y agoThat is a pretty offensive amount of light pollution going on the glimpses of street lights and car headlights in the pictures.
- PostOnce 7y agoWe need a law where if they want to use those at night, they need to cover them up somehow (has to be retractable, because they'll still want free natural sunlight in the daytime). That'll never happen though. "It costs too much". So, they'll steal the night sky from us and give us nothing in return. If public art is worth investing millions in per city, then what is the value of preserving the view of the night sky? Why don't we just paint everything grey and all wear grey clothes and eat soylent every meal and have nothing left that's beautiful. We can work in windowless offices to save money on windows. Maybe we can cover up the sunset next. Bah.
- Robotbeat 7y agoIt's less efficient to have all that light leaking to the sky. Makes sense to pass some sort of fee or regulation on massive light pollution like that. It's like methane leaks: it'd probably save some money to fix the problem, but the business deprioritizes it because the biggest cost is an externality which they do not (mostly) bear.
- nullc 7y agoIf you think the night sky hasn't been stolen already, then chances are you've just never been to someplace where it hasn't been. After that, it's all a matter of degree. It would be fairly straight forward to have ordinances that limit light pollution--- do a night time flyover (perhaps via drone), issue citations to any property with more than Y illumination facing up after hour X on more than N days out of M. But people don't care, perhaps because so many people have never actually seen a dark sky.
- bigiain 7y ago> But people don't care Can confirm: https://news.ycombinator.com/item?id=21277251 https://news.ycombinator.com/item?id=21277251
- starrio 7y agoSo beautiful and that's food right there.
- foofoo55 7y agoThe yellow/orange lights could very well be high-pressure sodium (HPS) lighting, the same type used in street lights prior to LEDs. Like the street lights, LED lights seems to have less wash and reflection back into the night sky than HPS, and use less power than HPS for the same growth effect on the plant. The industry is still transitioning to LED lighting due to cost and because some plants don't respond very well to LED light, so more development is required. I remember when HPS became a big thing in greenhouses and people would call the fire department at night thinking the glow meant a nearby fire.
- thrower123 7y agoThe best part of buying a house out of town was that I never have to look out my bedroom window at night and see that ever-present hellish orange haze from the street lights ever again.
- JohnJamesRambo 7y agoI think it is definitely possible. I don’t know of any led grow lights that make yellow tinged light, nor any reason they would want led lights with such a low color temperature. Double ended hps bulbs are still pretty efficient and I’m sure many greenhouses haven’t switched over. Gavita is a huge manufacturer and pioneer of lights like this and is based in the Netherlands.
- nullc 7y agoA lot of commercial lighting is switching off of HPS because of claims about LED lifetime costs based on (seemingly false) figures about durability. (E.g. drive around Los Angeles and see the dead/dying LED streetlights all over the place). I wouldn't be surprised if HPS lightning starts becoming unavailable as a result-- this has already happened with LPS lightning, with several manufacturers shutting down fabrication.
- curben 7y ago> claims about LED lifetime costs based on (seemingly false) figures about durability. (E.g. drive around Los Angeles and see the dead/dying LED streetlights all over the place). LED can be made durable if desired. In Detroit's case[1], the high failure rate can be attributed to manufacturer cutting corner on heat dissipation. [1]: https://news.ycombinator.com/item?id=19848794 https://news.ycombinator.com/item?id=19848794
- johnmorrison 7y agoThis is absolutely beautiful. I get the clear sky argument, but personally I think there's something amazing about having a city full of these at night. Imagine seeing such a city from the ISS.
- bearcobra 7y agoI’m curious if there is any kind of post-processing being done to these pictures. They are beautiful in a strange way
- tzs 7y agoOne interesting property of LEDs compared to many other lighting technologies is that they can be turned on and off very quickly. Suppose you made all your LED lights so that they alternated 2.08333 ms on, 2.08333 ms off. That's a 240 Hz flicker rate, which should be high enough that it won't bother people. Further, suppose you synchronized the flicker of all the lights in a city so that they were all on at the same time, and all off at the same time. Finally, suppose you made some goggles that had a shutter system opened for 1.5625 ms out of every 4.16667 ms, and synchronized it with the LED flickering so that the shutter opens 0.520833 ms after the LEDs start their off phase. The shutter will then be closing just as the LEDs turn on. By the time the shutter opens, the LEDs will have been off for 0.520833 ms. Light travels 156 km in that time, so the last light from the on phase of all LEDs within 156 km of the goggles will have already reached the goggles by the time the shutter opens. Question: would this effectively make the LEDs invisible to you through the goggles, while letting you see non-LED sources such as stars with no interference other than the 62.5% of their light you are losing during the times when the shutter is closed? One problem I can see (no pun intended) is that many LED lights actually use a bulb coated with phosphors, and the LED in the bulb is used to excite the phosphors which then glow giving off the light that we see. I'm not sure how quickly the phosphor stops glowing when the driving LED turns off.
- tambourine_man 7y agoThat’s a nice thought experiment but I believe reflection and scattering would still provide some sort of “after glow”
- est31 7y agoEven if a material reflects 100% of the incoming light, the light has to bounce around quite often in order to stick around for the time where the LEDs are off. In fact it has to travel 156 km somehow. Suppose a ray hits an object and doesn't get reflected. Then it has to be reflected at the right angle to hit another object, and another one and another one, until it has traveled the 156 km. Each time, it can also be reflected into the sky or be absorbed. I'd argue that within the time, most of the light will have escaped or been absorbed. Unless there are materials that have an after glow like you describe.
- djsumdog 7y agoUse to be farms in the middle of nowhere was where you could get away from the orange and yellow glows of the city streets. Massive farms that glow too? I've been reading a Sci-Fi series recently where one human sees a world totally dark at night except for a few human settlements .. and the character thinks about what Earth must have been like from orbit, before humanity arose.
- exabrial 7y agoThis is a mark of inefficiency, no?
- stordoff 7y agoHow is this inefficient?
- joe_the_user 7y agoThe light should be going to the plants, not space?
- Animats 7y agoLook at the sides of the greenhouses, which are far brighter than the roofs. The light from the roof is only what's reflected off the plants. LEDs are quite directional.
- joe_the_user 7y agoBy definition, all the light you can see is light that isn't going to the plants - light reflected off the plants could still be redirected, right?
- latchkey 7y agoWhen landing at an airport at night in Vietnam, you can see this all over the landscape. Much of it is for dragon fruit in off season... https://www.growables.org/information/TropicalFruit/DragonFruitSubTropicalQldClub.htm https://www.growables.org/information/TropicalFruit/DragonFr... https://english.vietnamnet.vn/fms/science-it/187197/vietnamese-scientists-invent-light-to-control-plant-flowering.html https://english.vietnamnet.vn/fms/science-it/187197/vietname...
- peter_d_sherman 7y agoInteresting links, thanks! Here's an excerpt which I found particularly interesting: "According to Nguyen Doan Thang from Rang Dong, the research team created more than 20 types of fluorescent powder to produce specialized lamps for chrysanthemum and dragon fruit tissue culture. The manufacturing processes are highly reliable, meeting the requirements for industrial production."
- micheljansen 7y agoUnfortunately the side effect of any artificial lighting in greenhouses is massive light pollution and pretty much no view of the night sky. I guess not being able to see the stars is a small price to pay for fresh vegetables year round, but having grown up far from greenhouses, I still miss the stars.
- rob74 7y agoStrangely beautiful, but also scary... makes you wonder what people will come up with once nuclear fusion makes electric energy even cheaper - I guess the amount of light pollution we have today will pale by comparison (no pun intended).
- pure-awesome 7y agoIronically, the lights in these "green" houses will be anything but green precisely for the reason that greenhouses are called that in the first place! Most leaves are green. This is to say that green light is reflected, and it's the OTHER wavelengths that are absorbed by the chlorophyll. So you need a light that is brighter in other parts of the spectrum where the absorption is strongest. Hence, a NON-green light. https://en.wikipedia.org/wiki/Chlorophyll https://en.wikipedia.org/wiki/Chlorophyll
- mikorym 7y agoHence that magenta... At least they can do the Avatar palette.
- DiabloD3 7y agoThe blurple lighting ended up being substandard for growing. Although you need to match the [Chlorophyll absorption spectrum](https://upload.wikimedia.org/wikipedia/commons/f/f6/Chlorophyll_Absorption_Spectrum.svg https://upload.wikimedia.org/wikipedia/commons/f/f6/Chloroph...), it isn't the only thing in a plant that absorbs light, and the proper spectrum is closer to [this](https://supergrowled.com/wp-content/uploads/Plant-Light-Absorption-Frequencies-1.jpg https://supergrowled.com/wp-content/uploads/Plant-Light-Abso...). The best performing LED grow light designs are essentially conventional full spectrum white light, sometimes boosted with additional far red, not the blurple lights that just make short unusually dense, flavorless plants.
- scotty79 7y ago
- manmal 7y agoI get that greenhouse windows have to be transparent during the day to let in the sun - so why don’t they add shutters that close at sundown and preserve even more of the LED light inside the greenhouses, reducing the necessary power input and solving the light pollution problem?
- toss1 7y agoMy first thought was how much energy they are squandering. Guessing the glass roof to collect sunlight in the day. Seems like merely rolling out mirrored mylar (horizontal) curtains at night would be worth it in energy cost savings alone, and of course create the benefit of minimizing light pollution.