Supplemental Greenhouse Lighting – Hacking the Sun to Grow Your Business

Pros and Cons of Supplemental Greenhouse Lighting 

Meeting Your Target Daily Light Integral (DLI)  

For most crops, there is a linear relationship between the total amount of light your plants receive and their growth. The daily light integral (DLI) is the sum of all photosynthetically active radiation (PAR) received by plants over the course of a 24-hour day. DLI is measured in moles of photons (mols) per square meter per day. Generally, the more photons – or the higher DLI – plants receive, the better the overall quality and production rates of plants. 

Many greenhouse growers are choosing LEDs for their supplemental lighting to increase DLI and eliminate seasonal shifts in light. This helps them increase year-round yields and keep production output stable for their customers. Andrew Fuller, Technical Director, at the UK’s Bridge Farm Group, noted: 

“Supplemental LED lighting allows us to provide the freshest and most flavourful herbs on the market 365 days a year despite seasonal changes.” 

It’s important to note that each plant species has an optimal light intensity above which light absorption and photosynthesis are not as efficient. Your lighting provider should map out a greenhouse lighting plan that considers the needs of all your individual crops.  

Year-Round Production 

With supplemental lighting, you are not bound to the seasons. Even in the dead of winter, with a high-quality LED grow light you can mimic ideal summer growing conditions. This will help you grow more plants faster and fit more grow cycles into a year, driving more profit for your business.
 

Enhanced Spectrum and Variable Spectrum Control 
 

Light works in synergy and the spectra in your supplemental lighting can help you achieve different goals at different phases of growth, from root establishment to plant finishing. HPS lighting, however, has a fixed spectrum and is not necessarily optimized for PAR and plant cultivation. 

Intelligent LED lighting and variable spectra controls can deliver the right light intensity (quantity), in the right ratio of wavelengths (quality), tuned to the DLI of your choosing (duration), and focused evenly on your plants (distribution). By harnessing these 4 key light properties, today’s grow facilities are ensuring optimal light exposure for their crops. 

Upfront and Operating Costs  
There is an upfront cost to adding supplemental greenhouse lighting, as well as the operating costs of running your lights day-to-day. There are, however, a few ways to mitigate those costs. 
 

Rebates & Incentives 
Generous rebates and incentives are being offered to growers who implement energy-efficient LEDs. These funds are being provided by government and utility organizations to encourage the switch from traditional lighting. They can help drive down the purchase price and considerably shorten your buy-back period. You may be surprised by the size of the rebates and incentives currently on offer. Download our eBook for Canada to find out what’s available to you. 
 

Energy Savings 
The US Department of Energy acknowledges that “LED is a highly energy-efficient lighting technology and has the potential to fundamentally change the future of lighting ….” LEDs use less wattage than HPS for a higher or similar level of light, leading to direct energy savings. Additionally, LEDs radiate very little heat, so energy isn’t wasted on cooling the space and plants. Crops also transpire less under LEDs, so dehumidification requirements are reduced. A combination of these factors helped US cannabis producer, Experience Organics, achieve a 50% reduction in energy costs with Heliospectra LED lighting and controls. 
 

Maintenance 
Unlike natural sunlight streaming through your greenhouse windows, HPS or LED lighting will need some maintenance and upkeep. While LEDs have a lifetime rating of over 50,000 hours, HPS lamps have a life expectancy of 24,000 hours and can experience a loss of efficacy within as little as 5,000 hours. 

When it comes to cleaning, our MITRA is IP66 rated and can be quickly hosed down, saving you time and effort, while HPS lamps and reflectors require regular, careful cleaning. Plus, LEDs don’t require bulb, ballast, or driver replacements, further driving down costs and using fewer consumables.