Energy saving cultivation of tulips and irises with 'Green label' greenhouse
Wagemaker Flowers B.V. in Hoogkarspel produces around 26 million tulips and 10 million irises. This happens in an environmentally friendly and energy conscious way in their 7000m² greenhouse that was completed by Ammerlaan Construction B.V. in 2008. The company developed a highly energy-efficient method of heating and cooling the greenhouse together with Sixways B.V. Consultancy. An energy reduction of up to 50% was achieved, compared to a conventional system.
Mr Wilfried Wagemaker, who runs the greenhouse company together with his brother Ad and his son Jeffrey, talks about his findings.
“Our family business has been engaged in the cultivation of open ground vegetables for 30 years. When the financial winters started lasting too long, we searched for a solution 18 years ago and we began cultivating irises in the old greenhouse. The vegetable cultivation was gradually phased out over a period of 10 years. We thought about increasing the cultivation of tulip bulbs in 2006, thanks to the commitment and the idea of Jeffrey, who had then graduated from the Higher School of Horticulture recently. We were busy working with tulips in the old greenhouse for about 2 or 3 years, while at the same time preparations began for the current project, because the small-scale approach in the old greenhouse was not economical and profitable.
The question then was: how could we seize the moment and set up an optimal production process, whereby we had three aspects in mind: environmental policy, energy policy and cost reduction in staff.
- Ground exchanger
A heat exchanger system was developed through Mr. Cees Besseling, together with Sixways B.V., whereby the summer heat of the greenhouse is stored in the ground. Poles that were equipped on the outer sides with ethylene tubing that was going to care of the storage of hot water were put 15 metres deep into the ground on an area of 10.000 m² . In the winter, this water, which still had a temperature of about 15 to 17°C, could once again be pumped through a heat exchanger and heated to 60°C and pumped into the under floor heating. The system works like a fridge, but with the proviso that the system, besides heating, can also provide cooling in the greenhouse. If a heat pump runs it produces both cold and heat in one operation and when you can utilise both energy flows, the heat pump is economical and profitable. That this is an extremely energy-efficient way of heating and cooling is evident from the fact that calculated energy savings of 50% can be achieved. Currently, after monitoring activities for 2 years, we are at over 40% and that will definitely be improved upon”, Wilfried Wagemaker says.
- Environmental Policy
“To be able to cope with the ever tougher rules in the environmental field, the ground exchanger was equipped with a closed water system. For the water supply and feeding of the plants, rain water is collected and reused again after filtering. Due to the closed system nothing is drained into the sewer system.
Partly because of this we have received certificates such as Green Label Greenhouse, MPS-A and MPS GAP. Only 5% of the greenhouses in the Netherlands qualify for the Green Label certification,” says a proud Wilfried Wagemaker.
“Due to the MEI - Environment Energy Innovation (Milieu Energie Innovatie)-, which provides the subsidy, we have constructed 200m² solar panels which provide some 40,000 KW/year of energy. We would have preferred to construct a wind turbine which could provide more electricity, but that is not allowed in this region. After all, we need approximately 1.5 million KW per year of energy for this greenhouse”.
- Multiple cultivation layers
“At the moment we have a double-bed system for the cultivation of our tulips. So, two layers of mobile cultivation layers under each other. This is excellent for tulips, because they require little light. We can even go to three cultivation layers in the future. The substructure of the greenhouse has been built for this by Ammerlaan Construction. For this, the total area of the greenhouse does not have to be increased. The heating supply and the internal transportation of the cultivation trays have also been built for this. So, with an extra cultivation layer the production will become more effective without any effect on the environment. In order to use the time between the tulip cultivations more effectively we are currently doing an experiment with irises in the new greenhouse, which we cultivated in the old greenhouse until now. It remains to be seen what the first harvest will bring, but it looks promising,” says Wilfried Wagemaker, who indicates he is very satisfied with the cooperation of several institutions and companies, such as Ammerlaan Construction BV.