How to quickly calculate the energy consumption and cost of light source required by greenhouse or plant factory?

First of all, we should make clear several knowledge points

1: PAR

Photosynthetically active radiation is also called par for short. It is called photosynthetically effective radiation in Chinese. Only light in the wavelength range of 400-700nm is effective for plant photosynthesis.

The wavelength of red light is 630-700 nm, and the wavelength of far red light is 705-740nm. The blue light is 400-450 nm and the ultraviolet wavelength is 315-400 nm. Plants change the way they grow with different colors of light (plant morphology), and too much infrared light (shadows from incandescent lamps or other plants) can cause plants to stretch too much. Too much blue light (such as fluorescent or metal halogen lamps) can cause plants to grow short. Therefore, choosing the right light source is very important for plant growth.

2: PPFD

PPFD (photosynthetic photon flux density) is called photosynthetic photon flux density in Chinese. This name is really around.. In fact, it is how much light touches every square meter per second. That is, a unit that measures the intensity of light. The unit is micromol / per square meter / second (µ mol / m2 / s). PPFD is generally calculated by ourselves according to the demand of greenhouse crops.

3: daily light integral (DLI)

Also known as sunlight integration, it is the sum of the effective light received in a day. The unit is mol / m2 / day. As I will say below, DLI value can usually be calculated from known PPFD and total illumination duration

Then calculate according to the following points;

1. The illumination area of a HPS Light or the illumination area of an LED Grow Light;

If we have a tomato greenhouse, usually our lighting goal is to achieve PPFD = 200 µ mol / m2 / s. When all fill lamps are used, we can calculate the area that a fill lamp can meet. (as mentioned earlier, in fact, the irradiation area of HPS is very large)

2. Quantity demand of high pressure sodium lamp or LED Grow Lighting

3. Energy consumption

The energy consumption of the light source is in watts (W), and each W is equal to joules per second (J / s). One kilowatt hour is one thousand watts per hour.

Then the energy consumption of a high-pressure sodium lamp is 1055w, which is 1.055kwh

4. Energy consumption cost

Electricity prices vary widely, depending on whether you use electricity for business or residential use

5. Fixed cost