TranscendL

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.

It will be interesting to see how the market scales. There are certainly advantages to large commercial greenhouses etc... but there is a quickly growing trend for small local producers that grow a few hundred or couple thousands plants at a time. They might service a grocery or a few restaurants. There is also a trend for people to grow at home, grove labs was already mentioned in this thread as an example. My guess, ultra-efficient, nearly fully automated indoor production facilities will be a major player. Labor and energy are the two biggest costs to production and there are emerging technologies to address both of these.

Regarding Europe, it hasn't been a primary focus for us but we have exported a few orders to the UK, Germany and Netherlands. I hadn't heard of pressure on vendors to screen their customers. I'll have to look into this.

Our orders so far have split about 50:50 between veggies and marijuana. The marijuana side of the business does certainly seem to overshadow the veggie side as far as general public interest goes!

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).

That's a great idea.

Etendue shouldn't be too much of a concern because we are emitting onto a relatively large space. We hadn't considered using a BEF but will certainly look into it.

Someone else mentioned using a holographic printed film for the same purpose of a BEF. Have you every used something like this?

It turns out that plants use more than just red/blue for photosynthesis. They do indeed absorb narrow bands of red/blue more strongly than other colors like green (this is why plants are green) but only absorb about 10% more efficiently.

The green light not absorbed is reflected. This gives the opportunity for green photons to reflect their way down to the bottom leaves for a more distributed growth.

We have built a number of lights with "focused" spectrum but haven't seen a benefit. In many plants, like "red" lettuces the leaves only turn red with a full spectrum (I have no idea why, a botanist might know the answer...)

We do see a benefit to skew the spectrum for many flowering/fruiting plants in later growth cycles and have a plan to come out with a "fruiting spectrum" in the future. This will part of our August Indiegogo campaign.

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.

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.

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.

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.

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.

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.

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.