The Daylight Greenhouse: up to 50% energy savings
The Daylight Greenhouse has diffuse insulating glass, but is also equipped with an installation that allows the grower to harvest excess heat. This system can cover approximately 50% of the heat requirement. Also, the greenhouse creates an optimal light distribution to the plant, resulting in better quality and production.
Special features of the Daylight Greenhouse:
The greenhouse deck is fully equipped with insulating glass; 16 Fresnel lenses are placed between the double glazing of the south deck (provided with anti-reflection coatings on the four glass sides for maximum light transmission).
The greenhouse is directly below the deck equipped with movable collectors, which consist of black painted tubes filled with running water.
The Fresnel lenses concentrate direct sunlight in thin focal lines. The black painted tubes are precisely placed in these lines, so the running water heats up by the radiation. The tubes automatically move with the position of the sun, so that they are always in the right position.
The ‘harvested’ energy (at Ter Laak approximately 20 m³ of natural gas equivalents per m²) is stored and reused by means of existing techniques (wells, heat pumps, day buffer systems).
Only 100% diffuse light remains for the plants, resulting in better light distribution. As a result, the greenhouse no longer needs a screen installation and in the winter the crop needs fewer hours of artificial lighting.
The first prototype of the Daylight Greenhouse (500 m²) was tested at the Wageningen University site. The resulting demo type (4,000 m²) was delivered to Ter Laak Orchids in Wateringen in 2014 and was extensively tested in collaboration with Wageningen UR. In 2017-2018, a second Daylight Greenhouse of five hectares was realised at Ter Laak. The Daylight Greenhouse was nominated for the GreenTech Innovation Award in 2014.