With the second crop in the Winterlight greenhouse at the Energy Innovation and Demo Centre (IDC) in Bleiswijk (NL) coming to an end, it’s time to draw some initial conclusions. The predominant feature of the greenhouse is its extremely high light transmittance.
Growers don’t only stand to gain from this in the winter but in the dark autumn months too: the 10%-plus light gain the designers were aiming for has turned out to be a reality. This not only means that all the partners involved in the project did a fantastic job, but also that the models used in the design process, such as RAYPRO, have proved their worth.
On the crop side, the two high-power crops we grew also yielded good results, despite the thrips problems we had in the first crop. With a few growing weeks to go, the tally is currently 268 cucumbers with an average fruit weight of 407 grams, bringing the total yield to more than 109 kg/m2. We are pleased with the outcome on the energy front, too. In this greenhouse, which is single glazed and has two high-transparency screens and a dehumidifier with heat recovery, we used less than 20 m3/m2 gas between the end of December and mid-November. But this did mean that we had to buy in around 13 kg of CO2.
Greenhouse builder Debets Schalke has a built one of the largest greenhouse for the cultivation of algae in the world in Austria. The greenhouse has a surface area of one hectare dedicated to the annual production of 100 tons of biomass derived from dry algae. When the full expansion of the greenhouse has been achieved in 2021 production figures will run to 300 tons per year.
The production of microalgae is a lucrative enterprise; the total turnover from the production of microalgae comes to billions of euros worldwide. Algae are relatively easy to grow and contain a high amount of high-quality fatty acids (Omega 3 & 6), natural colorants and valuable proteins.
The greenhouse built by Debets Schalke was tailored to the provide algae grower eparella with the facilities necessary for year-round production. A greenhouse with a post height of eight metres is exceptional, but necessary to enable the bioreactors that produce the industrial micro algae to operate to the best of their ability. Additionally, the greenhouse makes use of large ventilation systems to adequately regulate the extremely warm land climate in the greenhouse.
Versatile raw material
The microalgae grown by eparella are cultivated in 43,000 glass tubes distributed across 32 production chains: the bioreactors. It is possible to produce powdered algae of edible quality all year round by growing it in bioreactors. However, eparella does not use the micro algae exclusively for the production of foods and food supplements; eparella’s microalgae are also used as a raw material for cosmetics and medicines.
Because algae contain high-quality fatty acids like Omega 3 they are considered a sustainable alternative to fish oil. The production of algae does not create an imbalance in the existing ecosystems, as opposed to fisheries. eparella’s closed cultivation system ensures that the algae are grown in a pure and largely uncontaminated environment. As a result, the industrial microalgae are a clean raw material for sustainable products.
Text: Leo Hoekstra. Photo: Debets Schalke.