NL: Construction starts for Daylight Greenhouse Ter Laak Orchids

After many months of preparation, on February 15 the first pile was driven for the new phalaenopsis nursery of Ter Laak Orchids in the Netherlands. The construction of the steel substructure of the greenhouse starts in April. The design of the greenhouse is completed, the main choices for optimal alignment between climate, energy harvesting, energy saving, internal logistics and financial feasibility are made.

The greenhouse with a total size of 5 hectares is in its entirety executed as a Daylight Greenhouse. Four hectares is a ‘low’ greenhouse with a post height of 8.10 meters and one hectare is a ‘high’ greenhouse with a second cultivation layer. The post height of the 'high' greenhouse is a whopping 11.70 meters.

The low greenhouse is executed as a 9.0 meter girder greenhouse with a section size of 5.0 meters. On the roof, insulating glass will be installed with main dimensions of 2,600 x 1,652 mm. The southern roof's glass consists of 91+ Albarino tempered float glass, with four-sided AR-coating and filled with argon. 16 fresnel lenses are placed inside the cavity. The northern roof's glass consists of tempered Albarino High Haze float glass filled with argon.

The direct sunlight is concentrated by the lenses in the southern roof on one line and collected by two movable collectors. The water in the collectors is heated up from 20 °C to about 45 °C. Ter Laak is using the collected heat, with the aid of a buffer, to heat the greenhouse 24 hours per day. The excess heat is stored in aquifers so that in colder periods it is available to heat the greenhouse.

The entire Daylight Greenhouse is equipped with an installation for Next Generation Growing. This installation will suck in dry air through the gable ends, possibly mix it with greenhouse air and, if necessary, will additionally heat up the air up to the indoor temperature on the spot. Then the installation will distribute the air through transparent hoses to the cultivation departments. The heat exchangers in the air treatment units are fed with low temperature (LT) heat supplied from the collectors.

It is expected that this greenhouse will harvest more than 10,000 MWh of solar energy through this heat collector annually. With the use of insulating glass in the deck and the highly insulating sandwich panels in the facades, this greenhouse also saves considerably on gas consumption. In addition to heat harvesting, the Daylight Greenhouse will annually consume approximately 25% less gas per m2 than any other modern greenhouse.

The Daylight Greenhouse and associated energy systems can make a significant contribution to make the potted plants and cut flowers cultivation more sustainable. The concept therefore fits seamlessly in the ambition of the greenhouse sector to reduce CO2 emissions. The objective of the horticultural sector to achieve a fully sustainable and economically viable energy supply in 2050, comes a big step closer with this greenhouse.

During the past period, Ter Laak Orchids, Technokas and Bode Project and Engineering invested a lot of time in the continued development of this type of greenhouse. In addition, the financial feasibility was studied intensively and looked into from several angles. The project was partly funded by the Dutch Ministry of Economic Affairs.