The opening ceremony yesterday in Bleiswijk, Holland
China is home to more than one million hectares of solar greenhouses. The low-tech structures, which use the principle of storing heat from the sun in a wall, are the most common type of greenhouse used by Chinese farmers. The heat that is stored in the wall by day, is used to heat the greenhouse by night. "It's a simple but efficient design for the local Chinese circumstances that can be built with local materials. It works very well, however, sometimes it can be quite difficult to control the climate", explained Feije de Zwart of Wageningen UR.
A typical Chinese greenhouse in Shougang
A typical Chinese greenhouse in Shougang. The greenhouse can be isolated with a ''carpet" screen.
For this reason, Dutch horticultural technology suppliers Hoogendoorn, Svensson, Ridder and HortiMaX have teamed up to develop new solutions that can be adopted in the Chinese solar greenhouse. The new greenhouse at Wageningen UR is equipped with special ventilation, a special screen through which humidity and vapor can pass without loss of energy. The greenhouse also has climate and irrigation systems that can control multiple greenhouses in series, which can increase the ROI for Chinese growers. Researchers are looking at other solutions as well, such as additional humidity control systems.
The Chinese greenhouse in Holland, with ventilation
At the moment there are two cucumber crops planted in the greenhouses. This crop is used to fine-tune the installation of the technology and gain the first experiences. In the summer a first tomato crop will be planted to simulate the tomato season in China. This crop will be planted simultaneously with a compare crop planted in a similar solar research greenhouse in Shougang, China.
The comparison greenhouse in China is exposed to a completely different climate. In order to simulate the Chinese circumstances better, the solar greenhouse in Bleiswijk is equipped with heating inside the wall. This way, the Chinese circumstances can be partly simulated, based on the data that is coming directly from the greenhouse in Shougang.
Partners of the Chinese project: Joep van den Bosch, Hortimax, Stefano Hiwat from Hoogendoorn, Hugo Plaisier and Paul Arkensteijn with Ludvig Svensson and Joachim Keus, Ridder. Delphy and Wageningen UR also participate in the project.