Author Archives: hq_l1huwa


References Cited

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[54] NetZero // Urban Agriculture, “Quantum Wavelength Measurement,” 14 06 2018. [Online]. Available:
[55] NetZero // Urban Agriculture, “Sales Projections,” 27 06 2018. [Online]. Available:


Weather Damage

One of the primary reasons we advocate controlled environment agriculture is to eliminate damage of crops grown outdoors and in high tunnels that are not protected from weather damage. One farmer using a high tunnel to grow microgreens had the entire crop delivered by air mail free of charge to the next county when Hurricane Matthew visited, and had damage to the high tunnel frame in addition to the ripped plastic.

Microgreens in High Tunnel

Hurricane Matthew – Damage to High Tunnel Frame and Plastic

Sales Projections


10″ between pans, 4 pans per rack, 30″x60″ pan size, 4 trays per pan, 1 pound expected yield per tray, 1 week harvest, $80 per pound price
One rack of 4 pans 30″x60″ each: 800W LED, 960W total
(4 pans/rack)*(4 trays/pan)*(1 pound/tray) = 16 pounds per week yield
(16 pounds)*($80/pound) = $1,280 per week income
($1,280/week)*(52 weeks/year) = $66,560 annual income
One 40′ cargo container with 8 racks of pans: 6.4 kW LED, 7.7 kW total
(8 racks/container)*(4 pans/rack)*(4 trays/pan)*(1 pound/tray) = 128 pounds per week yield
(128 pounds)*($80/pound) = $10,240 per week income
($10,240/week)*(52 weeks/year) = $532,480 annual income

Tall Plants

48″ between pans, 2 pans per rack, 30″x60″ pan size, 8 of 10 gallon fabric pot with ceramic substrate per pan, 1 pound expected yield per pot, 3 month harvest, $800 per pound price
One rack of 2 pans 30″x60″ each: 1600W LED, 1920W total
(2 pans/rack)*(8 pots/pan)*(1 pound/pot) = 16 pounds per harvest yield
(16 pounds)*($800/pound) = $12,800 per harvest income
($1,280/harvest)*(4 harvests/year) = $51,200 annual income
One 40′ cargo container with 8 racks of pans: 12.8 kW LED, 15.4 kW total
(8 racks/container)*(2 pans/rack)*(8 pots/pan)*(1 pound/pot) = 128 pounds per harvest yield
(128 pounds)*($800/pound) = $102,400 per harvest income
($102,400/harvest)*(4 harvests/year) = $409,600 annual income


The Vero SE 29 Generation 7 COB LED array currently in production generates 100 W of true LED power that produces a photosynthetic photon flux density of 4600 umol/m^2/s from a single chip in our system, and is rated by the manufacturer to generate 201 W LED by changing the drive current from 2.1 A to 3.6 A. It connects to our system with inexpensive 2-conductor 20 AWG wires that push into place without any soldering.

Cree 3070N CoB LED array in earlier prototype increased power output

The forward voltage @ 1900 mA Tc=85 deg C is 36.2V. 36.2V*1.9A=68.8W. The forward voltage @ 1900 mA Tc=25 deg C is 42V. 42V*2.8A=117.6W. The percent change is 71% allowing the system to operate with 71% fewer LED lights.

Bridgelux CoB LED array currently in production increased power output

At 3.6 A, the forward voltage is 55.8 V resulting in 201.0 W LED output from a single chip.

The percent change is 192% allowing the system to operate with 192% fewer LED lights.

part number on chip – 35E10K0B7


80 CRI

full part number – BXRC-35E10K0-B-7x-SE

Performance at Commonly Used Drive Currents:

900 mA 49.6 V 44.7 W
1200 mA 50.5 V 60.6 W
1800 mA 52.0 V 93.6 W
2700 mA 54.1 V 146.1 W
3600 mA 55.8 V 201.0 W

10 year warranty

Light Coverage

According to the manufacturer, the light source we had used in one of our prototypes has a beam spread of 115 degrees.

Although we ran the LED array at 1.4 A constant current, we are able to safely double the current to 2.8 A by keeping the case temperature under 25 degrees Celsius with our heat sink that has a large plate transfer area coupled with water cooling.

The doubling of the current doubles the amount of light from the same device, and cuts the number of lights a farmer needs in half.

With the 115 degree light spread, we are able to space our microgreens pans vertically every 7.5″ with nutrient film hydroponics, 8.5″ with coconut weave mat, and 9.5″ with Speedling floating trays.

Pest and disease pressures are not addressed and nutritional advantages are not supported

Pest and Disease Pressures

Controlled environment agriculture does not have the exposure of outdoor grown crops where pests, diseases, and weather damage most likely occur. Each rack of pans operates independently of the others in its own closed loop, and racks of pans may be further isolated inside grow tents that operate as a clean rooms with completely independent environments. Chieri Kubota addresses chemical fumigants to control pest and disease in crops not grown in a controlled environment in her video (5:12) and wrote a supporting letter for our grant

Nutritional Advantages

Nutritional advantages for microgreens as opposed to their mature counterparts has been extensively researched and published.


Cooling the Lights

Microgreens grown without soil in a coconut mat with our first commercial system that went into service 11/11/2017, the day after we filed for our patent.

We had a person concerned about the recirculating water used to cool the LEDs being returned to hydroponics as waste heat. The recirculating water used to cool the LEDs has no measurable waste heat. The thin steel pans with large surface areas dissipate heat from the lights at the case for the LEDs mounted directly to the steel with a thermal adhesive. The large surface areas of water on one side and steel on the other effectively reach a thermodynamic equilibrium with the controlled environment that has temperature and humidity control. The recirculating water had no measurable temperature change with the lights on or off measured with a Fluke Model 179 Multimeter that has an integrated temperature probe with a thermocouple that measures -40 to 260 deg C.

Heat from LEDs recirculates to the top pan, and is re-used for that germination area. We eliminate the heating pad that others use for their germination area. The thermodynamic design with cooling from the recirculation of water eliminates the active cooling that others use with nearly 40 mechanical and electrical parts including steel chassis, power supply, machined aluminum heat sink, and fans. Our system is the most efficient system regarding energy and cost on the market today. We reduce waste in heat and electrical energy. Our power supply operates at 95% efficiency with no loss in the electronic dimmer used to match the LED output to the measured photosynthetic photon flux density (PPFD) at the plant canopy. This closed loop tuning of the light to the plant is the most efficient method possible. Our LED has a output (PPFD) of 4600 umol/m^2*s at the surface measured with my Quantum PAR Meter. When a plant needs 800 umol/m^2*s at the plant canopy at a distance that varies as the plant grows, we are able to tune in exactly what the plant needs without any waste. Our research involves light frequencies outside the currently measured 400 – 700 nm for photosynthetically active radiation (PAR). One specific frequency produces a 20% increase in crop yield that is non trivial.

LED lighting chassis, fans, power supply, hardware, and finned aluminum heat sink eliminated

Cree CXA3070 LED

System with Rack of Stacked Pans

2.1 A Power Supply

Bridgelux LED 2.1 A on bottom, and Cree LED 1.4 A on top

Microgreens sell for up to $80 per pound from an urban agriculture company in Richmond, Virginia

Chieri Kubota – Video on Optimizing Plant Performance

Chieri Kubota’s video published on the SciTechReports YouTube channel on June 11, 2012 titled “Optimizing Plant Performance – Plants Spliced, LED Lights Glow, & Strawberries Bloom” addresses the need for plants to have specific colors of LED lights including far red (2:20), red (2:45), and blue (3:17) to engineer plants with superior traits. She also mentions enhancing the flavor of strawberries in a controlled environment (4:38), lack of strawberries grown in green houses in the United States as opposed to Japan (5:02), chemical fumigants to control pest and disease in crops not grown in a controlled environment (5:12), and that a strawberry crop is a good candidate for local production with better worker efficiency and production (5:44).

Microgreens – Market Rate

At Food Peddler Co-op in Vancouver, Canada, the market rate for kohlrabi microgreens ($20/140g*28g/oz *16oz/lb*1 US$/1.32 Canadian$) is US $48 per pound. At Gourmet Greens, LLC in Richmond, VA, the specialty microgreens (sweet golden corn, hot radical radish, and micro spicy mix) 2016 price was $48 per pound. The 2018 price is $80 per pound for swiss chard, beets, and basil. The market rate has nearly doubled in two years.

2016 Microgreens Market Rate

2018 Microgreens Market Rate

Vint Cerf on Sensor Feedback for Optimized Growing Potential

Vint Cerf is on the Board of Directors at National Science Foundation, and gave me permission to use his quote about my patent pending design.

“Your ability to control light spectrum remotely and under computer management supports an intriguing scenario in which sensor feedback can be used to optimize growing potential.” Vinton G. Cerf, Internet Pioneer 10/2017

I had communicated with Vint Cerf about using Internet of Things (IoT) with IP on everything along with digital signal processing for closed loop control of urban agriculture light spectrum. We had met around the turn of the millennium, and had discussed using similar technology in the audio spectrum. Bringing that technology into urban agriculture will give us unprecedented control over the daily light integral over the entire life cycle of plants.

Vint Cerf and Jim Ray