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Transcend (YC S15) Launches an Extra-Efficient LED Light for Indoor Farmers

45 points by tlb 11y ago

Someone1234 11y ago
It doesn't matter so much now with legalisation, but I cannot help but wonder what impact these high efficiency LED lights would have had on the illegal weed business. A lot of police forces did things like use infrared cameras and electricity usage to find people growing such things, but with these LEDs they could remain more undetected for longer. But on a more broad note: Indoor farming has real potential, in particular for certain types of crops. Not only do indoor farms use less water (which takes energy to produce and transport), but requires less or no pesticides, can be grown out of season, and you're less subject of good/bad weather patterns. I don't think we'll see this type of thing for inexpensive crops that use up a lot of land (e.g. corn) but we might be more expensive crops that are fairly land efficient (e.g. nuts, fruits, etc).
- Turing_Machine 11y ago
  A guy is setting up a large-scale LED vegetable farm in Alaska, where getting fresh produce in the winter is quite expensive, since of course it has to be shipped in by a fairly fast (= costly) method. See: http://www.adn.com/article/20150315/vertical-farm-poised-rise-inside-old-mat-maid-building http://www.adn.com/article/20150315/vertical-farm-poised-ris...
- marssaxman 11y ago
  I actually built an experimental LED grow light for a friend several years ago, back before legalization. She was not particularly worried about getting busted, but reducing the cost of electricity was a really big deal, since power and rent defined the cost of business. The system was a few years ahead of its time, as LED emitters were not yet powerful enough to replace her high-pressure sodium lamps, but it worked well for getting her new clones started. Beyond the simple efficiency of LEDs as light producers, the fact that we didn't have to waste any power generating yellow-green light meant the power requirement was something like 10% of what it had been with HPS. Clorophyll absorption peaks are at 430nm and 662nm, so we used LEDs with peak wavelengths near those values, and while the light appeared dim and purple to human eyes, the plants loved it.
- steckerbrett 11y ago
  Fruit and nuts are probably not going to see this sort of thing, primarily because the trees take a very long time to come to maturity. With some varieties you might be looking at a decade of care before you actually get any yield from them at all.
themgt 11y ago
Interesting tech, but quite expensive. I'm looking to do some indoor herbs/greens in my office, but these lights look maybe 5x more expensive than the multi-color diode competitors. I'd be curious to see comparison with PAR spectrum and plant grow results against similar wattage multi-color LED.
- roel_v 11y ago
  But their claim is 5x longer lifespan, too. And where do you buy 250w led grow lights for 200$?
  - themgt 11y ago
    Here's a 300w for $135: http://www.amazon.com/GalaxyhydroTM-Spectrum-Greenhouse-Flowering-Growing/dp/B00INM0750/ http://www.amazon.com/GalaxyhydroTM-Spectrum-Greenhouse-Flow... Or a 1200w for $369: http://www.amazon.com/KingTM-Spectrum-360-860nm-10bands-Flower/dp/B00WHF830K/ http://www.amazon.com/KingTM-Spectrum-360-860nm-10bands-Flow... I actually have free electricity at my office, otherwise I'd run the numbers to see the cost savings. 5x longer lifespan ... I'd want an independent review.
    - roel_v 11y ago
      Oh wow those are very good prices. If they perform well (or even half of what they promise), then yes these will give the upmarkets ones a run for their money. Of course the same can be said for almost all goods. I'd love to have time to experiment with an indoor aquaponics garden in my basement, and try out various lights.
- TranscendL 11y ago
  The major difference is upfront cost vs. cost of ownership. If you purchase the "cheap" multi-color products you will end up consuming MUCH more energy. The difference is much more than the upfront cost of the lights. There are some well designed multi-color "pink" lights out there and there cost is similar to ours. A 325watt multi-color design has similar light output to our 230 watt remote phosphor design.
Theodores 11y ago
There are a lot of vegetables and fruits that I do not buy due to the air miles. For instance those nice peas in pods from Kenya. Those things don't get here (the UK) by boat whereas bananas from the Caribbean do get here by boat. Boat is acceptable to me, good for trade and enough arrives by boat for a decent meal to be made. In theory these lights change everything, why grow peas in Kenya, put them on a plane and send them 1/4 the way around the world when a greenhouse in the Home Counties will do nicely? The cannabis angle is pretty good too. As things stand growing those plants takes a stupendous amount of energy with all the problems of ventilation, mould growth, noise from the ventilation and the need to 'not get caught'. With this technology those that can hold down a job can get growing their own without having to have the huge 'leccy bill or having to be friends with dealers. I like the lateral thinking of tuning the light to suit photosynthesis by using phosphors, I am surprised that has not been possible before. One day this will seem so obvious yet it wasn't until this product came along.
- ars 11y ago
  You have got to be kidding. You are worried about air miles, but are willing to accept artificial light? Do you just want to feel like you are being environmentally friendly, or do you actually want to be environmentally friendly? I've been surprised at how many people only want to feel that way, but don't actually care about being environmentally friendly. (A good example of this is locavores.) > of tuning the light to suit photosynthesis by using phosphors, I am surprised that has not been possible before. It has been thought of before, people have been doing it for decades. This is just an incremental improvement.
  - oldmanjay 11y ago
    Is it your contention that LED lighting uses as much energy as flight?
    - ars 11y ago
      Comparing light to grow plant, vs fuel to fly the fruits of that plant? LED lighting use more, even without doing the calculations I feel quite confidant in saying that it uses much more.
Animats 11y ago
Why are those lights so big? Indoor farms, especially in Japan, have been using LED lights for a while. Red/blue combos, in the pink/purple range, seem to work best.[1] The big advantage of LED lighting is not the reduced power consumption, but the reduced heat. The lamps can be closer to the plants without cooking them, which means the trays can be stacked closer and the density of the operation goes up. For most non-druggie applications, the plants aren't that tall. So small, distributed lighting units are used, instead of huge ceiling lamps. Some plants can be overclocked. They do need a light/dark cycle, but it can be shorter than 24 hours. The life cycle of the plant is then sped up. [1] http://www.economist.com/news/science-and-technology/21602194-indoor-farming-may-be-taking-root-light-fantastic http://www.economist.com/news/science-and-technology/2160219...
- TranscendL 11y ago
  I'm Brian, the founder of Transcend. Each light is 19 pounds and is about 10"x8". There are two reasons the light is the size that it is. First temperature. We have a passive heat sink with fins and a plastic remote phosphor sheet. Both have to stay relatively cool and more surface area makes this possible. Its funny, the first fixture we built and sampled to growers was about 25x smaller. We used an active heat sink and a glass phosphor sheet. A common complaint was "why is this so small?" I want my lights to be "big and strong". We took this feedback and decided to move to passive design. Our original logic was that smaller is better, especially in a greenhouse. The most efficient light is one that is off and the less shading of sunlight the better.
  - deleted 11y ago
    [deleted]
  - mabbo 11y ago
    Thanks for coming here to reply to comments! I think small lights could be a really good market for you, for all the urbanites like me, living in condos. Make a tiny kit that can grow herbs or lettuce at an accelerated rate using little power because of LEDs, and I'd buy it in a second. As it stands, I think a 1m strand of TL-RL20 will be a purchase for me soon, and I'll build the kit myself.
roel_v 11y ago
The rope lights are especially cool for indoor hydro pole installations. Still, $1000 + 1$/day in electricity, it could grow let's say 100 kg of strawberries / year with that much light (that's an optimistic estimate), which would cost say 500$ to buy in a supermarket. That's not counting the cost of the rest of the installation, fertilizer etc. Could make sense at huge scale, but not for home sized installations, I think.
- jws 11y ago
  Yeah, the numbers are funny. They claim they will pay for themselves in energy savings in a year, but that seems to be against some unnamed alternative in their "up to 70% more efficient" claim. High pressure sodium lamps (apparently the norm for indoor commercial food growing) look to be about 1.8µmoles/watt, compared against the ">2 µmoles/watt" of these lights, well, its going to take a long time to save $1000 in energy on a 250 watt lamp. Lamp lifetime may tip the scales in favor of these LED lamps. Lamp size may also help, I used a 600 watt high pressure sodium lamp in my calculation against the 250 watt LED. (µmoles are new units to me. I think I got through the lumens-lux-µmoles calculation correctly, but maybe not.)
  - TranscendL 11y ago
    The numbers are heavily influenced by cost of electricity and time of use. Payback ranges from 1-5 years with an average user seeing payback in about 3. Average 600W HPS lamps are 1.0-1.3 µmoles/watt. A complete fixture consumes 660 watts with ballast losses. They generally lose about 20% of their light due to reflectors (omni-directional lamp in a directional application). This means that our 2.0 µmoles/watt fixture at 230 watt consumption can replace a 660 watt HPS fixture, provide the same amount of light, and have a nice payback.
    - roel_v 11y ago
      Here's what I didn't get from your website: there are typically two wavelengths you're interested in for growing plants, depending on the phenological stage: a red and a blue (I can't remember the exact numbers, but the band is quite narrow). How can it be that your lamps have higher efficiency despite providing a complete spectrum? I don't know anything about light physics, hence my question; intuitively, I'd say you could have higher 'yield' by focusing all energy you put in to one wavelength (or at least, a narrow band).
bastijn 11y ago
Interesting, philips (nl) launched the exact same somewhere last week. http://www.lighting.philips.nl/application_areas/horticultural/cityfarming.wpd http://www.lighting.philips.nl/application_areas/horticultur... sorry for the Dutch link, you can switch at the top to English.
ernestipark 11y ago
If you're interested in indoor growing, Grove Labs is building an entire home aquaponics appliance. https://grovelabs.io/ https://grovelabs.io/
wnkrshm 11y ago
Don't you lose a lot of usable energy by not having any optics to shape the radiation? The phosphor surfaces will just diffusely glow. Of course, with an emitting area that big, you also need huge optics to control it properly
- TranscendL 11y ago
  Phosphors are interesting in that they emit in 360 degrees. We have a "recycling cavity" behind the phosphor plates that reflects "backward" emitting photons. The design of this cavity is key to an efficient remote phosphor system. As far as forward throw, the plate is a lambertian emitter. This means ~80% of the light is in a 60 degree beam angle and nearly >95% within 70 degrees.
  - jacksonzhang 11y ago
    How about the photon energy loss of phosphors due to Stokes shift?
    - TranscendL 11y ago
      Yes, we lose there is energy losses from Stokes shift. For example, when we shift from a high energy blue photon to a lower energy red photon we lose the difference in photon energy as heat. Blue LEDs are approx 55% efficient and red LEDs 35% efficient. Even with Stokes shift losses our fixtures end up being more efficient. If, however, blue LEDs and red LED emitted at similar efficiencies our technology wouldn't work. We'd lose too much energy in the conversion. Luckily (for us) blue LED efficiency is projected to increase more quickly over the next few years than other colors (more R&D dollars behind them).
  - wnkrshm 11y ago
    If you already have a light-recycling setup for the phosphor - maybe you could additionally use brightness-enhancement films to use for light recycling in angular space. Just like in liquid crystal screens, BEFs could refract light rays with high exit angles back towards the phosphor, giving you a collimation of about 45° for rectangular, linear prism films. But of course, conservation of optical étendue ('optical entropy' so to say) can't be cheated and absorption and scattering losses will be the trade-off for better collimation.
logfromblammo 11y ago
"...blue photons, which are the most efficient type of photon..." Argh. Plants require light at 450 nm (blue) and light at 650 nm (red) to experience normal growth, and 730 nm (far-red) is also required to flower normally. (That last one may be important to growers of certain plants valued for their flowers and/or fruits.) Phytochromes and photropins are the plant pigment-hormones that govern the plant life cycle. They respond to those 3 critical wavelengths of light to allow the plant to guess the time of day and the season of the year. Some plants also need a dark phase to "sleep", but it doesn't have to be as long as an actual night. Blue light is likely most efficient at forcing the increase in green plant mass. That is, it makes bigger leaves and longer stems. That isn't always what you want for indoor farming. The ideal indoor grow light would have a programmable, timed output of those three critical wavelengths of light, with a different ideal program for each type of plant. You may wish to start with red light, to germinate the seeds, go to blue light for rapid growth, then manipulate the plant into flowering out of season by switching between the two reds. Transcend also needs a smaller, programmable 650/730nm light to offer a complete indoor farming solution, particularly for plants that do not get natural sunlight. It wouldn't need to use nearly as much energy, as it is being used primarily for hormonal signaling rather than photosynthesis.
- deckar01 11y ago
  Most efficient to produce not most efficient for plant growth. Context: "The company has developed a wavelength conversion system that uses phosphorous to convert blue photons, which are the most efficient type of photon, into any other color photon."
  - logfromblammo 11y ago
    If you're using phosphors, you do want to make blue or UV. It's far easier to step a photon down in energy than to absorb multiple lower energy photons and emit one at higher energy. But the highest efficiency color for LEDs to produce largely depends on what Cree and Nichia are doing this year. Unfortunately, most of the readily available numbers tout luminous efficiency rather than raw light power. That's fine if you're looking for a reading light, but chlorophyll does not have the same absorption spectrum as the opsins in the human eye. You have to look for "wall-plug efficiency", which is less commonly reported. So with respect to photons emitted per watt, I'm not sure which LED chemistry takes the prize. It depends on the temperature and input power, too. You can achieve 200% wall-plug efficiency, but only if you're converting picowatts of electricity into picowatts of photons in a hot LED. This is not possible (economically) for grow lights. The benchmark for grow lights is the low-pressure sodium lamp, at about 38% efficiency. LEDs maybe get 30-65%, considering transformers, internal resistance, quantum efficiency, reflective losses at the die-capsule interface, etc. Higher efficiency comes from more expensive components. As for chemistry, InGaN efficiency drops at longer wavelengths, and AlInGaP efficiency drops at shorter wavelengths, leaving a big efficiency trough in the green range. (Fortunately for this, plants don't need green.) I suspect that AlInGaP LEDs in the orange range are more efficient than visible blue InGaN LEDs, but this is hard to show with a lazy web search. So when you say "most efficient" you really have to be very explicit about the application. That was my implied complaint about that sentence in the article.
Zak 11y ago
Trancend’s bulbs differ from typical LED lights because they only use blue light. The company has developed a wavelength conversion system that uses phosphorous to convert blue photons, which are the most efficient type of photon, into any other color photon. Typical LEDs used for illumination are blue LEDs with a phosphor coating to produce white. Transcend is doing essentially the same thing, but the goal is to produce wavelengths optimal for plant growth instead of a broad spectrum for illumination. The biggest difference in implementation looks to be that Transcend is separating the phosphor from the emitter while most LEDs used for illumination bond the phosphor directly to the emitter.
nkurz 11y ago
The descriptions on Transcend's website make me feel uneasy. I presume they have a solid product, but it feels like it's being oversold. Each of our remote phosphor fixtures are rated to last for 96,000 hours to 90% output. That's over 10 years of 24/7 use. How has this been tested? And if it is true, why is there a 5 year warranty rather than a 10 year? And what level of decline in output is covered by the 5 year warranty? Efficiency: >2.0 μmoles per watt Presuming you mean "per joule" rather than "per watt", this is very close to the claimed efficiency of the underlying Royal Blue LED, and (I think) much higher than any white LED. While I can believe there is some benefit from the lower temperature of the remote phosphor, this would be a remarkably high number for a full spectrum light. How has this been measured?
- Havoc 11y ago
  >remarkably high number for a full spectrum light. I don't think growing lights are full spec
  - nkurz 11y ago
    Some are, some aren't. I was going by Transcend's web site which says that they are full spectrum: "The fixture emits full-spectrum PAR light for 96,000 hours (10 years of 24/7 use)." In theory, you can get a significant gain in efficiency by choosing specific wavelengths. In practice, it's difficult figure out exactly what these wavelengths should be, and to match them to existing high efficiency emitters.
- TranscendL 11y ago
  Yes, it has been tested. The industry standar LM-80 lifetime testing of the LED shows an L70 lifetime of ~300,000 hours. We are operating the LEDs at a lower temperature meaning they should theoretically last even longer. This is how we specify the 96,000 hour operating time to 90% The Royal Blue LEDs we use have a ~55% EQE (external quantum efficiency). This gives a μmoles per joule a fair amount above 2.0. We lose a few photons during the conversion process and that drops us down to about 2.0. We have a ~30% efficiency improvement over standard white LEDs because the phosphor is remote. The gain is 100% due to to the recycling cavity and omnidirectional nature of phosphors.
drfritznunkie 11y ago
I've been spending some time myself designing remote phosphor lighting and I'm wondering if they've really developed a new remote phosphor technology, or if they're sourcing a custom phosphor blend and substrate from someone like Intematix. Also curious if they're using a film (like WhiteOptics White97) or having the cavities coated (I forget the product name). None of the coatings were cheap when I was researching them, but a % or two better than the films. I'd love see the LED driver board on these... But anyhow: It's incredibly cool stuff, especially when you show someone the raw blue leds (blindingly bright), then drop a remote phosphor over it. Kudos for going for it, and good luck. I wish I had your fortitude!
- TranscendL 11y ago
  We build our own remote phosphor components and in some cases source components from companies like Intematix. We have a solid "side business" where we formulate and produce custom remote phosphor components for non general lighting applications. For the recycling cavity we do indeed use WhiteOptics. We used Furakawa in our last design and have had success with both.
- hooo 11y ago
  How do you get started designing lighting like this? Are there any good resources online for building your own LEDs etc.
- hooo 11y ago
  How do you get started designing lighting like this? Are there any good resources online for building your own LEDs etc.
technotony 11y ago
Congratulations on launching! We were in a previous YC batch (glowing plant, S14) and grow lots of plants indoors. We are interested in lighting systems which promote early flowering, as this shortens our product development cycle. Can your lights be set to encourage this (ie can you balance vegetative growth vs flowering?)
- TranscendL 11y ago
  Thanks! It is possible. We are coming out with a new LED T5 lamp where we can easily customize the output spectrum. It would be fun to work together to find out the ideal spectrum.
eonw 11y ago
considering that not all plants need the same spectrums throughout growth, i wonder if they have any plans to allow tuning of such things. if you are trying to grow the best, energy efficiency doesn't matter as much as top quality product at any cost. I think heliospectra lights allows you to change their output via an open API. with the legalization of marijuana already happening in some states and pending in many others, the lighting industry is full of fluff right now and too many players... will be interesting to see who stands, who falls and who M&A. I think many growers will stick to HIDs until someone can prove LEDs, Plasma or induction not only delivery the same quality product, but can actually do it cycle after cycle, these 50k hour guarantees are suspicious at best.
- TranscendL 11y ago
  We don't have spectral tuning functionality at the moment but it's something we are working on. A number of customers growing fruiting/flowering plants have asked for this sort of spectral control. For non-fruiting plants there seems to be less of a demand. We plan on having a next gen remote phosphor design with spectral control within the next 12 months.
  - eonw 11y ago
    thanks for your response. i would imagine spectral controls to be less useful for leafy greens. will the spectral controls be remote controllable? ie; an api over some type of wifi connection?

45 points by tlb 11y ago

It doesn't matter so much now with legalisation, but I cannot help but wonder what impact these high efficiency LED lights would have had on the illegal weed business. A lot of police forces did things like use infrared cameras and electricity usage to find people growing such things, but with these LEDs they could remain more undetected for longer. But on a more broad note: Indoor farming has real potential, in particular for certain types of crops. Not only do indoor farms use less water (which takes energy to produce and transport), but requires less or no pesticides, can be grown out of season, and you're less subject of good/bad weather patterns. I don't think we'll see this type of thing for inexpensive crops that use up a lot of land (e.g. corn) but we might be more expensive crops that are fairly land efficient (e.g. nuts, fruits, etc).

Turing_Machine 11y ago
A guy is setting up a large-scale LED vegetable farm in Alaska, where getting fresh produce in the winter is quite expensive, since of course it has to be shipped in by a fairly fast (= costly) method. See: http://www.adn.com/article/20150315/vertical-farm-poised-rise-inside-old-mat-maid-building http://www.adn.com/article/20150315/vertical-farm-poised-ris...
marssaxman 11y ago
I actually built an experimental LED grow light for a friend several years ago, back before legalization. She was not particularly worried about getting busted, but reducing the cost of electricity was a really big deal, since power and rent defined the cost of business. The system was a few years ahead of its time, as LED emitters were not yet powerful enough to replace her high-pressure sodium lamps, but it worked well for getting her new clones started. Beyond the simple efficiency of LEDs as light producers, the fact that we didn't have to waste any power generating yellow-green light meant the power requirement was something like 10% of what it had been with HPS. Clorophyll absorption peaks are at 430nm and 662nm, so we used LEDs with peak wavelengths near those values, and while the light appeared dim and purple to human eyes, the plants loved it.
steckerbrett 11y ago
Fruit and nuts are probably not going to see this sort of thing, primarily because the trees take a very long time to come to maturity. With some varieties you might be looking at a decade of care before you actually get any yield from them at all.

themgt 11y ago

Interesting tech, but quite expensive. I'm looking to do some indoor herbs/greens in my office, but these lights look maybe 5x more expensive than the multi-color diode competitors. I'd be curious to see comparison with PAR spectrum and plant grow results against similar wattage multi-color LED.

roel_v 11y ago
But their claim is 5x longer lifespan, too. And where do you buy 250w led grow lights for 200$?
- themgt 11y ago
  Here's a 300w for $135: http://www.amazon.com/GalaxyhydroTM-Spectrum-Greenhouse-Flowering-Growing/dp/B00INM0750/ http://www.amazon.com/GalaxyhydroTM-Spectrum-Greenhouse-Flow... Or a 1200w for $369: http://www.amazon.com/KingTM-Spectrum-360-860nm-10bands-Flower/dp/B00WHF830K/ http://www.amazon.com/KingTM-Spectrum-360-860nm-10bands-Flow... I actually have free electricity at my office, otherwise I'd run the numbers to see the cost savings. 5x longer lifespan ... I'd want an independent review.
  - roel_v 11y ago
    Oh wow those are very good prices. If they perform well (or even half of what they promise), then yes these will give the upmarkets ones a run for their money. Of course the same can be said for almost all goods. I'd love to have time to experiment with an indoor aquaponics garden in my basement, and try out various lights.
TranscendL 11y ago
The major difference is upfront cost vs. cost of ownership. If you purchase the "cheap" multi-color products you will end up consuming MUCH more energy. The difference is much more than the upfront cost of the lights. There are some well designed multi-color "pink" lights out there and there cost is similar to ours. A 325watt multi-color design has similar light output to our 230 watt remote phosphor design.

Theodores 11y ago

There are a lot of vegetables and fruits that I do not buy due to the air miles. For instance those nice peas in pods from Kenya. Those things don't get here (the UK) by boat whereas bananas from the Caribbean do get here by boat. Boat is acceptable to me, good for trade and enough arrives by boat for a decent meal to be made. In theory these lights change everything, why grow peas in Kenya, put them on a plane and send them 1/4 the way around the world when a greenhouse in the Home Counties will do nicely? The cannabis angle is pretty good too. As things stand growing those plants takes a stupendous amount of energy with all the problems of ventilation, mould growth, noise from the ventilation and the need to 'not get caught'. With this technology those that can hold down a job can get growing their own without having to have the huge 'leccy bill or having to be friends with dealers. I like the lateral thinking of tuning the light to suit photosynthesis by using phosphors, I am surprised that has not been possible before. One day this will seem so obvious yet it wasn't until this product came along.

ars 11y ago
You have got to be kidding. You are worried about air miles, but are willing to accept artificial light? Do you just want to feel like you are being environmentally friendly, or do you actually want to be environmentally friendly? I've been surprised at how many people only want to feel that way, but don't actually care about being environmentally friendly. (A good example of this is locavores.) > of tuning the light to suit photosynthesis by using phosphors, I am surprised that has not been possible before. It has been thought of before, people have been doing it for decades. This is just an incremental improvement.
- oldmanjay 11y ago
  Is it your contention that LED lighting uses as much energy as flight?
  - ars 11y ago
    Comparing light to grow plant, vs fuel to fly the fruits of that plant? LED lighting use more, even without doing the calculations I feel quite confidant in saying that it uses much more.

Animats 11y ago

Why are those lights so big? Indoor farms, especially in Japan, have been using LED lights for a while. Red/blue combos, in the pink/purple range, seem to work best.[1] The big advantage of LED lighting is not the reduced power consumption, but the reduced heat. The lamps can be closer to the plants without cooking them, which means the trays can be stacked closer and the density of the operation goes up. For most non-druggie applications, the plants aren't that tall. So small, distributed lighting units are used, instead of huge ceiling lamps. Some plants can be overclocked. They do need a light/dark cycle, but it can be shorter than 24 hours. The life cycle of the plant is then sped up. [1] http://www.economist.com/news/science-and-technology/21602194-indoor-farming-may-be-taking-root-light-fantastic http://www.economist.com/news/science-and-technology/2160219...

TranscendL 11y ago
I'm Brian, the founder of Transcend. Each light is 19 pounds and is about 10"x8". There are two reasons the light is the size that it is. First temperature. We have a passive heat sink with fins and a plastic remote phosphor sheet. Both have to stay relatively cool and more surface area makes this possible. Its funny, the first fixture we built and sampled to growers was about 25x smaller. We used an active heat sink and a glass phosphor sheet. A common complaint was "why is this so small?" I want my lights to be "big and strong". We took this feedback and decided to move to passive design. Our original logic was that smaller is better, especially in a greenhouse. The most efficient light is one that is off and the less shading of sunlight the better.
- deleted 11y ago
  [deleted]
- mabbo 11y ago
  Thanks for coming here to reply to comments! I think small lights could be a really good market for you, for all the urbanites like me, living in condos. Make a tiny kit that can grow herbs or lettuce at an accelerated rate using little power because of LEDs, and I'd buy it in a second. As it stands, I think a 1m strand of TL-RL20 will be a purchase for me soon, and I'll build the kit myself.

roel_v 11y ago

The rope lights are especially cool for indoor hydro pole installations. Still, $1000 + 1$/day in electricity, it could grow let's say 100 kg of strawberries / year with that much light (that's an optimistic estimate), which would cost say 500$ to buy in a supermarket. That's not counting the cost of the rest of the installation, fertilizer etc. Could make sense at huge scale, but not for home sized installations, I think.

jws 11y ago
Yeah, the numbers are funny. They claim they will pay for themselves in energy savings in a year, but that seems to be against some unnamed alternative in their "up to 70% more efficient" claim. High pressure sodium lamps (apparently the norm for indoor commercial food growing) look to be about 1.8µmoles/watt, compared against the ">2 µmoles/watt" of these lights, well, its going to take a long time to save $1000 in energy on a 250 watt lamp. Lamp lifetime may tip the scales in favor of these LED lamps. Lamp size may also help, I used a 600 watt high pressure sodium lamp in my calculation against the 250 watt LED. (µmoles are new units to me. I think I got through the lumens-lux-µmoles calculation correctly, but maybe not.)
- TranscendL 11y ago
  The numbers are heavily influenced by cost of electricity and time of use. Payback ranges from 1-5 years with an average user seeing payback in about 3. Average 600W HPS lamps are 1.0-1.3 µmoles/watt. A complete fixture consumes 660 watts with ballast losses. They generally lose about 20% of their light due to reflectors (omni-directional lamp in a directional application). This means that our 2.0 µmoles/watt fixture at 230 watt consumption can replace a 660 watt HPS fixture, provide the same amount of light, and have a nice payback.
  - roel_v 11y ago
    Here's what I didn't get from your website: there are typically two wavelengths you're interested in for growing plants, depending on the phenological stage: a red and a blue (I can't remember the exact numbers, but the band is quite narrow). How can it be that your lamps have higher efficiency despite providing a complete spectrum? I don't know anything about light physics, hence my question; intuitively, I'd say you could have higher 'yield' by focusing all energy you put in to one wavelength (or at least, a narrow band).

bastijn 11y ago

Interesting, philips (nl) launched the exact same somewhere last week. http://www.lighting.philips.nl/application_areas/horticultural/cityfarming.wpd http://www.lighting.philips.nl/application_areas/horticultur... sorry for the Dutch link, you can switch at the top to English.

ernestipark 11y ago

If you're interested in indoor growing, Grove Labs is building an entire home aquaponics appliance. https://grovelabs.io/ https://grovelabs.io/

wnkrshm 11y ago

Don't you lose a lot of usable energy by not having any optics to shape the radiation? The phosphor surfaces will just diffusely glow. Of course, with an emitting area that big, you also need huge optics to control it properly

TranscendL 11y ago
Phosphors are interesting in that they emit in 360 degrees. We have a "recycling cavity" behind the phosphor plates that reflects "backward" emitting photons. The design of this cavity is key to an efficient remote phosphor system. As far as forward throw, the plate is a lambertian emitter. This means ~80% of the light is in a 60 degree beam angle and nearly >95% within 70 degrees.
- jacksonzhang 11y ago
  How about the photon energy loss of phosphors due to Stokes shift?
  - TranscendL 11y ago
    Yes, we lose there is energy losses from Stokes shift. For example, when we shift from a high energy blue photon to a lower energy red photon we lose the difference in photon energy as heat. Blue LEDs are approx 55% efficient and red LEDs 35% efficient. Even with Stokes shift losses our fixtures end up being more efficient. If, however, blue LEDs and red LED emitted at similar efficiencies our technology wouldn't work. We'd lose too much energy in the conversion. Luckily (for us) blue LED efficiency is projected to increase more quickly over the next few years than other colors (more R&D dollars behind them).
- wnkrshm 11y ago
  If you already have a light-recycling setup for the phosphor - maybe you could additionally use brightness-enhancement films to use for light recycling in angular space. Just like in liquid crystal screens, BEFs could refract light rays with high exit angles back towards the phosphor, giving you a collimation of about 45° for rectangular, linear prism films. But of course, conservation of optical étendue ('optical entropy' so to say) can't be cheated and absorption and scattering losses will be the trade-off for better collimation.

logfromblammo 11y ago

"...blue photons, which are the most efficient type of photon..." Argh. Plants require light at 450 nm (blue) and light at 650 nm (red) to experience normal growth, and 730 nm (far-red) is also required to flower normally. (That last one may be important to growers of certain plants valued for their flowers and/or fruits.) Phytochromes and photropins are the plant pigment-hormones that govern the plant life cycle. They respond to those 3 critical wavelengths of light to allow the plant to guess the time of day and the season of the year. Some plants also need a dark phase to "sleep", but it doesn't have to be as long as an actual night. Blue light is likely most efficient at forcing the increase in green plant mass. That is, it makes bigger leaves and longer stems. That isn't always what you want for indoor farming. The ideal indoor grow light would have a programmable, timed output of those three critical wavelengths of light, with a different ideal program for each type of plant. You may wish to start with red light, to germinate the seeds, go to blue light for rapid growth, then manipulate the plant into flowering out of season by switching between the two reds. Transcend also needs a smaller, programmable 650/730nm light to offer a complete indoor farming solution, particularly for plants that do not get natural sunlight. It wouldn't need to use nearly as much energy, as it is being used primarily for hormonal signaling rather than photosynthesis.

deckar01 11y ago
Most efficient to produce not most efficient for plant growth. Context: "The company has developed a wavelength conversion system that uses phosphorous to convert blue photons, which are the most efficient type of photon, into any other color photon."
- logfromblammo 11y ago
  If you're using phosphors, you do want to make blue or UV. It's far easier to step a photon down in energy than to absorb multiple lower energy photons and emit one at higher energy. But the highest efficiency color for LEDs to produce largely depends on what Cree and Nichia are doing this year. Unfortunately, most of the readily available numbers tout luminous efficiency rather than raw light power. That's fine if you're looking for a reading light, but chlorophyll does not have the same absorption spectrum as the opsins in the human eye. You have to look for "wall-plug efficiency", which is less commonly reported. So with respect to photons emitted per watt, I'm not sure which LED chemistry takes the prize. It depends on the temperature and input power, too. You can achieve 200% wall-plug efficiency, but only if you're converting picowatts of electricity into picowatts of photons in a hot LED. This is not possible (economically) for grow lights. The benchmark for grow lights is the low-pressure sodium lamp, at about 38% efficiency. LEDs maybe get 30-65%, considering transformers, internal resistance, quantum efficiency, reflective losses at the die-capsule interface, etc. Higher efficiency comes from more expensive components. As for chemistry, InGaN efficiency drops at longer wavelengths, and AlInGaP efficiency drops at shorter wavelengths, leaving a big efficiency trough in the green range. (Fortunately for this, plants don't need green.) I suspect that AlInGaP LEDs in the orange range are more efficient than visible blue InGaN LEDs, but this is hard to show with a lazy web search. So when you say "most efficient" you really have to be very explicit about the application. That was my implied complaint about that sentence in the article.

Zak 11y ago

Trancend’s bulbs differ from typical LED lights because they only use blue light. The company has developed a wavelength conversion system that uses phosphorous to convert blue photons, which are the most efficient type of photon, into any other color photon. Typical LEDs used for illumination are blue LEDs with a phosphor coating to produce white. Transcend is doing essentially the same thing, but the goal is to produce wavelengths optimal for plant growth instead of a broad spectrum for illumination. The biggest difference in implementation looks to be that Transcend is separating the phosphor from the emitter while most LEDs used for illumination bond the phosphor directly to the emitter.

nkurz 11y ago

The descriptions on Transcend's website make me feel uneasy. I presume they have a solid product, but it feels like it's being oversold. Each of our remote phosphor fixtures are rated to last for 96,000 hours to 90% output. That's over 10 years of 24/7 use. How has this been tested? And if it is true, why is there a 5 year warranty rather than a 10 year? And what level of decline in output is covered by the 5 year warranty? Efficiency: >2.0 μmoles per watt Presuming you mean "per joule" rather than "per watt", this is very close to the claimed efficiency of the underlying Royal Blue LED, and (I think) much higher than any white LED. While I can believe there is some benefit from the lower temperature of the remote phosphor, this would be a remarkably high number for a full spectrum light. How has this been measured?

Havoc 11y ago
>remarkably high number for a full spectrum light. I don't think growing lights are full spec
- nkurz 11y ago
  Some are, some aren't. I was going by Transcend's web site which says that they are full spectrum: "The fixture emits full-spectrum PAR light for 96,000 hours (10 years of 24/7 use)." In theory, you can get a significant gain in efficiency by choosing specific wavelengths. In practice, it's difficult figure out exactly what these wavelengths should be, and to match them to existing high efficiency emitters.
TranscendL 11y ago
Yes, it has been tested. The industry standar LM-80 lifetime testing of the LED shows an L70 lifetime of ~300,000 hours. We are operating the LEDs at a lower temperature meaning they should theoretically last even longer. This is how we specify the 96,000 hour operating time to 90% The Royal Blue LEDs we use have a ~55% EQE (external quantum efficiency). This gives a μmoles per joule a fair amount above 2.0. We lose a few photons during the conversion process and that drops us down to about 2.0. We have a ~30% efficiency improvement over standard white LEDs because the phosphor is remote. The gain is 100% due to to the recycling cavity and omnidirectional nature of phosphors.

drfritznunkie 11y ago

I've been spending some time myself designing remote phosphor lighting and I'm wondering if they've really developed a new remote phosphor technology, or if they're sourcing a custom phosphor blend and substrate from someone like Intematix. Also curious if they're using a film (like WhiteOptics White97) or having the cavities coated (I forget the product name). None of the coatings were cheap when I was researching them, but a % or two better than the films. I'd love see the LED driver board on these... But anyhow: It's incredibly cool stuff, especially when you show someone the raw blue leds (blindingly bright), then drop a remote phosphor over it. Kudos for going for it, and good luck. I wish I had your fortitude!

TranscendL 11y ago
We build our own remote phosphor components and in some cases source components from companies like Intematix. We have a solid "side business" where we formulate and produce custom remote phosphor components for non general lighting applications. For the recycling cavity we do indeed use WhiteOptics. We used Furakawa in our last design and have had success with both.
hooo 11y ago
How do you get started designing lighting like this? Are there any good resources online for building your own LEDs etc.
hooo 11y ago
How do you get started designing lighting like this? Are there any good resources online for building your own LEDs etc.

technotony 11y ago

Congratulations on launching! We were in a previous YC batch (glowing plant, S14) and grow lots of plants indoors. We are interested in lighting systems which promote early flowering, as this shortens our product development cycle. Can your lights be set to encourage this (ie can you balance vegetative growth vs flowering?)

TranscendL 11y ago
Thanks! It is possible. We are coming out with a new LED T5 lamp where we can easily customize the output spectrum. It would be fun to work together to find out the ideal spectrum.

eonw 11y ago

considering that not all plants need the same spectrums throughout growth, i wonder if they have any plans to allow tuning of such things. if you are trying to grow the best, energy efficiency doesn't matter as much as top quality product at any cost. I think heliospectra lights allows you to change their output via an open API. with the legalization of marijuana already happening in some states and pending in many others, the lighting industry is full of fluff right now and too many players... will be interesting to see who stands, who falls and who M&A. I think many growers will stick to HIDs until someone can prove LEDs, Plasma or induction not only delivery the same quality product, but can actually do it cycle after cycle, these 50k hour guarantees are suspicious at best.

TranscendL 11y ago
We don't have spectral tuning functionality at the moment but it's something we are working on. A number of customers growing fruiting/flowering plants have asked for this sort of spectral control. For non-fruiting plants there seems to be less of a demand. We plan on having a next gen remote phosphor design with spectral control within the next 12 months.
- eonw 11y ago
  thanks for your response. i would imagine spectral controls to be less useful for leafy greens. will the spectral controls be remote controllable? ie; an api over some type of wifi connection?