How To Oct 22, 2019

How to Guarantee Your Greenhouse Light Levels Year-Round

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Ensure Your Greenhouse Light Levels

Giving your crop adequate and consistent light is a challenge since weather patterns change throughout the day and light levels change throughout the year.

It’s important to ensure your light targets are hit for consistent crop production year-round.  Although you don’t want too much light or you risk overspending or even worse, damaging your crop.

The newest and most effective way to maximize production while minimizing costs is with the world’s first integrated grow light sensor.   The LumiGrow Light Sensor Module comes standard when you order your smartPARTM Wireless Control System and plugs directly into your LumiGrow fixtures.  The sensor collects solar light data and automatically adjusts your light fixtures to hit a consistent daily light integral (DLI) every day of the year.

The following video shows a Cabrillo College study and real-life example of LumiGrow Light Sensor Module in action during two consecutive summer days in a California.  The first day is sunny and the second cloudy.  Still, the results are surprising as to how much a lighting strategy can be improved even within a sunny state like California!

See how the LumiGrow Light Sensor performs in a greenhouse at Cabrillo College on both a sunny and a cloudy day.

Increase Lettuce Yields by 40%

Yes, now we know that sounds like a bold claim, but hear us out. In a study done at Cabrillo College on Skyphos lettuce found that we could boost baby lettuce yields by 40% and mature lettuce yields by 15%.  This was achieved by utilizing the same amount of energy that your lighting system is already using and using our integrated light sensor to deliver this light more appropriately over a longer period of time throughout the day.

The breakthrough discovery is now being termed as a “High Yield Photoperiod”. “High Yield Photoperiod” lighting strategies dramatically boost crop yields and reduce energy-costs for lettuce and are applicable across any number of crops.

Read the full Cabrillo College Research Report here

How Does the Light Sensor Work?

The LumiGrow Light Sensor is truly a unique solution, different from any other horticultural sensor on the market.  The integrated light sensor collects data and combines with historical solar data, then uses artificial intelligence algorithms to adjust your fixtures to achieve your target Daily Light Integral (DLI) every day of the year.  This means the total amount of light that you plants accumulate throughout the day (solar + supplemental light) ends up being the same each day of the year regardless of what’s going on with the weather outside.

What’s more is that by using artificial intelligence, the lights can slowly ramp up or ramp down intensity to create changes in your lighting similar to natural light for a healthier lighting environment.

The result is a perfect lighting environment for your plants to thrive every day of the year.

Let’s now discuss how this lighting strategy worked at Cabrillo College in the video above.

Overview of a Sunny Greenhouse Day

In the video above, you see how the LumiGrow Light Sensor tracks ambient sunlight in the greenhouse and supplements only what’s needed to reach the target light levels set for the crop’s photoperiod (4am-10pm).

Beginning at the start of the photoperiod on August 2, starting at 3am the sensor triggers the lights to come on to start delivering light to the crop. When the sun comes out, the lights dim and then turn off throughout the sunny day, letting the sun deliver the majority of the crop’s light needs.

When the sun starts to go down for the day and the light levels diminish, the lights slowly ramp in intensity through the end of the photoperiod at 10pm, delivering the target light levels for the day.

Graph of a sunny day in the greenhouse

Wow, now that’s a lot of additional light required to optimize yields for a sunny day in California!

Overview of a Cloudy Greenhouse Day

The next day starts the same way with the light sensor triggering the lights to come on at the beginning of the set photoperiod at 4am.

When the sun starts to rise, the lights dim and then turn off, just like the day before, but because the light levels are lower on this cloudy day, the sensor triggers the lights to come back on and scale up throughout the day to deliver more supplemental light.


The lights remain on throughout the cloudy day, smoothly adjusting in intensity to achieve its target DLI, and providing supplemental light until the photoperiod ends at 10pm.

Ideal Lighting Conditions Year-Round

Of course you will want to track how much energy you’re using by hitting your yield quotas year-round.  The next step after running your lighting automation is to check your energy-use, solar lighting trends, and supplemental lighting usage.

grow light metrics
A look inside smartPAR software’s analytics feature

By comparing days you can then choose to adjust your target DLI to make decisions that are best for your commercial greenhouse business.

Combining the Art and Science of LED Cultivation

Now let’s think about the way that growers cultivate with supplemental lighting today.  Many growers simply hang a lighting layout that they hope will be adequate.

It’s true that the addition of static supplemental lighting strategies will increase yields initially by filling in the natural fluctuations in sunlight due to weather and the sun’s position in the sky related to the greenhouse structure.

Though, static lighting strategies don’t account for:

  • DLI Saturation Point
    • Using static lighting strategies almost always ensures that you’re exceeding or falling short of your DLI saturation point, therefore leaving yield on the table or overspending on electricity
  • Year-Round Production
    • Often times, growers turn the lights on solely in the winter and fall seasons.  As shown in the above video, this often means that you’re losing out on significant yield below the DLI saturation point even if it appears bright outside. This often means that you’re losing out on significant yield even in sunny regions
  • Smart Lighting Technology
    • Some growers may try to optimize with a 3rd-party sensor on their greenhouse.  The problem is that these sensors are not fully integrated with adjustable lighting and artificial intelligence is not used so they cannot be as accurate.  Additionally, if tied to HPS lighting then the long cooling and warming periods make a target DLI impossible

    There is an art to cultivation that requires a grower to learn their crop and environment and provide consistent care.  Lighting automation as seen above only helps a grower provide this level of care more consistently while also caring for the health of their business.

    Scheduling lighting programs simply means growers can improve yields while also freeing up time.  Essentially ensuring that growth will be healthy while energy-costs remain low.

Contact LumiGrow Today for a Quote!!
Designed for Greenhouse & High Bay Applications
Designed for High Performance Vertical Applications
Wireless Grow Light Control