In this article you will learn about greenhouse lighting design with HPS, Hybrid and 100% LED design.
What is greenhouse lighting?
The main source of lighting in the greenhouse is the natural daylight. The natural daylight can potentially emit 300-500 micromole. However direct sunlight on plants can cause heat-issues and stress. Greenhouses have adopted diffused plastic, glass, or screens to avoid these heat and stress issues. In addition the day length or season will impact the actual micromole that reaches the plant. Therefore supplemental lighting is widely used to increase yield and consistency.
What is HPS, Hybrid and 100% LED lighting design?
Lighting in the greenhouse is supplemental. For supplemental lighting there are several technologies. HPS is High Pressure Sodium light. Hybrid is a combination of HPS and LED. 100% LED is using only Light Emitting Diode technology in the greenhouse.
Advantages and disadvantages of HPS
HPS lighting is a commonly used supplemental light-source. This light has a proven track record in the greenhouse and the initial investment is modest. HPS lights are available in a fixed formfactor (lamp) with a fixed spectrum that cannot be adapted, the light emits heat and it is relatively energy consuming with a short lifespan.
Advantages and disadvantages of LED
With LED lighting growers can increase lighting intensity, there is more freedom to make a continuous lighting line, the spectrum can be optimized, the fixture itself emits little heat and it is relatively energy efficient. These features allow growers to manage plant health and development so that the quality and the yield can be increased.
However the upfront investment is larger and it makes sense from a total cost of ownership point of view which includes running costs and replacement costs.
Advantages and disadvantages of Hybrid
The greenhouse market might transition to LED solutions in a gradual way. While newly built greenhouses may consider 100% LED, existing greenhouses or growers with well established growth management methods might want to opt for a combination of HPS and LED. This is called hybrid lighting. In this scenario LED lighting may boost the energy efficiency and enhance the spectrum of light. HPS may give some heat if that is desired by the grower or in using more LEDs if the outside temperatures increase. A hybrid system also reduces the total investment and allows a grower to make a cost-effective upgrade of their current installation.
Lightscripts
There is increasing evidence that light can be optimized for the grower’s goal, crop variety, growth environment and growth stage. Some lighting companies provide lighting recipes, which enable the grower to select a very specific light source and light setting. However growers may grow various crops and at various growth stages. Therefore lightscripts are more suitable. Lightscripts can optimize the light based on crop, growth stage, grower’s goal or even simply based on the natural daylight that is measured in the greenhouse and then optimizing it to offset and seasonal influence. This can make a significant impact to the financial bottom line of the greenhouse and makes it an attractive option for growers that focus on quality and innovation. To enable lightscripts a fixture would need to have the flexibility to adjust the spectrum. Examples of flexible spectrum fixtures are the HortiPower Grower 1 or HortiPower Nurser 1.
What do you need to make a lighting design simulation?
A lighting design simulation is a computer calculation based on the dimensions of the greenhouse and selected light fixtures. Based on a few parameters the grower can see the intensity of the lights, the uniformity and energy use. Inputs that one might need for the lighting design simulation are the greenhouse dimensions, current installation height, current crop and growth stage and any problems or wishes from the grower.
What fixture (light) is recommended?
HortiPower Grower will be introduced soon and is perfect to replace 300W Son-T or 600W Son-T lamps. Contact us for more information at info@hortipower.com