In a period of high energy prices, greenhouse heating, and especially lighting are costly activities. Lighting less and utilizing existing gas contracts to produce power can provide better operating efficiency than using your own power. At Kas als Energiebron (Greenhouse as an Energy Source), we read that four scenarios were calculated at the request of a group of gerbera growers in 2022.
The variations of the scenarios are around the concept of the existing CHP plant mainly to be used for selling electricity instead of its own lighting. When sold on the public grid, electricity represents a high value, especially during the day and early evening. The residual heat from the CHP can be used for stronger gerbera cultivation. Illuminating the crop less means not only a reduction in power requirements but also a reduction in heat requirements. For balanced cultivation, lower light input leads to lower 24-hour temperatures.
Learning points
From an analysis of cultivation strategies in gerbera in winter 2022-2023, the following learning points were formulated:
- Flower diameter and, flower stem quality, and shelf life decrease too much in unilluminated cultivation. With limited exposure, a clear improvement in quality can be seen there.
- After 7-10 days, a clear quality improvement can be seen to the limited use of lighting after December 1.
- Production with no lighting in units has been well above pre-estimated.
Unilluminated growers only saw production peak around week 9-10, which was also common in the past;
All learning points can be read here at Kas als Energiebron.