Artificial light is the most expensive growth factor in greenhouse production but it cannot be omitted. It is essential to plant growth and development in the winter months. However, Danish greenhouse growers can save a lot of light energy by listening to plant requirements.
The amount of energy used for lighting can be reduced significantly in commercial greenhouses by turning on the artificial light later in the autumn and turning it off earlier in the spring. By following the development in the natural light conditions it is possible to set a limit of e.g. 20 to 25 percent as the minimum amount that artificial light should be of the total amount of light.
Read more about the project here.
LED can substitute traditional lamps in greenhouses
As an alternative, currently most lights in greenhouses are high pressure lamps giving a yellow glow over the greenhouses at night. However, very recent experiments show that high output light-emitting diode lamps (LED) can directly substitute the old lamps resulting in a saving of 60 percent on the electricity bill.