Differences in production costs of HPS lamps and LEDs
The advantages of high pressure sodium lamps and LEDs are obvious compared to conventional light sources. When the plant canopy is top-filled with high-pressure sodium lamp fill light and LED grow light offering red and blue light, the plant can achieve the same output. LED only needs to consume 75% of energy. It has been reported that under the conditions of the same energy efficiency, the initial investment cost of LED is 5~10 times that of the high-pressure sodium lamp device. Because of the initial high cost, in 5 years, the cost of every molar lighting quantum of LED is 2~3 times higher than that of the high-pressure sodium lamp.
For flowerbed plants, the 150W high pressure sodium lamp and the 14W LED can achieve the same effect which means the 14W LED is more economical. The LED plant lamp chip only offer the light needed by the plant. It will increasing efficiency by removing unwanted light. The use of LEDs in sheds requires a large number of equipment, and the cost of one-time investment is large. For individual vegetable farmers, investment is more difficult. However, LED energy saving can recover the cost in two years, so the high-quality LED plant lights will greatly improve the economic benefits after two years.
Green plants absorb most of the red-orange light with a wavelength of 600-700 nm and blue-violet light with a wavelength of 400-500 nm, and only slightly absorb the green light with a wavelength of 500-600 nm. Both high-pressure sodium lamps and LEDs can meet the illumination needs of plants. The original research purpose of researchers using LEDs was to improve energy efficiency and to reduce operating and management costs, and to improve the quality of commercial crops. In addition, LED can be widely used in the production of high-quality pharmaceutical crops. What’s more, Scholars have pointed out that LED technology has great potential in improving plant growth.
The high-pressure sodium lamp is moderately priced and can be accepted by the majority of farmers. Its short-term effectiveness is better than that of LED. Its complementary light-filling technology is relatively mature and is still in large-scale use. However, high-pressure sodium lamps require the installation of ballasts and related electrical appliances, increasing their cost of use. Compared with high-pressure sodium lamps, LEDs have narrow spectral tunability, safety and reliability. LEDs have flexibility in plant physiological test applications. However, in actual production, the cost is higher. The light decay is larger. And the service life is far below the theoretical value. In terms of crop yield, LED has no obvious advantage over high-pressure sodium lamps. In specific use, it should be reasonably selected according to actual conditions such as cultivation needs, application objectives, investment capacity and cost control.