INTEGRATIVE USE OF SOLAR THERMIC ENERGY FOR THE REGULATION OF TEMPERATURE IN GREENHOUSES

Due to increase of the cost of competitiveness in greenhouse production, both from the economical and technological points of view, the authors carried out trials integrating traditional methods of greenhouse thermal regulation during the winter season to ensure suitable temperatures for plant development.
The use of solar energy was evaluated as an additional renewable energy source to help achieve fuel savings.
The solar thermic system was set up in late December 2006 and was fully functional by February 2007. The system was installed in a 400 m² greenhouse equipped with a 80.000 Kcal/h warm air generator with an estimated consumption of ~ 8,88 l/h of diesel oil.
Another greenhouse with the same characteristics was used as a control to estimate diesel oil savings.
The following data were daily collected: diesel oil consumption by the two warm-air generators, energy stored inside the water tank, energy distributed in the greenhouse, minimum and maximum temperatures inside the tank and hours of sunlight.
Preliminary results show that it is possible to obtain diesel oil savings of approximately 15%. This result was observed only when the environmental conditions allowed the system to accumulate sufficient heat.
It was observed that to obtain this performance level, the water in the tank needs to reach temperatures above 50°C or, better, to accumulate more than 40 kWh, which is possible only if the day is at least partially sunny.

International Symposium on High Technology for Greenhouse System Management: Greensys2007

A. Grassotti, S. Cacini, E. Taibi

renewable energy, thermal solar panels, heating systems, greenhouse conditioning

https://doi.org/10.17660/ActaHortic.2008.801.97