Sustainable energy consumption at Duijvestijn Tomaten
Since 2011 Duijvestijn Tomaten uses geothermal energy. Geothermal allows heating of the glasshouse in a sustainable way. This creates a huge relief to the environment. Due to the heat from the earth, Duijvestijn Tomaten burnes no more fossil fuel. This results in highly reduced CO2 emissions.
How does geothermal energy work? And why is it sustainable?
In September 2010 Duijvestijn Tomaten started with a geothermal drilling. The idea for geothermal existed for a long time and recieved much attention in the field of preparation.
When using geothermal energy you use the heat generated (at great depths) below the ground. This heat is stored in sand and water in porous rock layers. The water is deep enough under the surface to keep warm, but not too deep, so it can be transported to the surface.
This is done by drilling into the stratum where the water is embedded. From this layer, the warm water is transported to the surface. At the surface the hot water is pumped through a heat exchanger. In this heat exchanger, the heat of the water heats up a second stream of water. This second water stream is used for the heating of the greenhouse. The pumped water is then pumped back into the stratum to warm up again for reuse.
CHP: Combined Heat and Power
Besides the geothermal source, Duijvestijn uses CHP’s. The CHP’s are needed in extremely cold periods and apply as a backup of the geothermal resource. In times of maintenance of the geothermal resource, it remains possible to ensure the growth of our tomato plants, with enough heating.
A CHP (Combined heat and power installation) produces heat and electricity simultaneously in an installation. There is considerably less fuel (natural gas) needed in order to produce the energy than in a regular power plant. The efficiency of a CHP is great, because heat and electricity is made simultaneously. A CHP net therefore consumes less energy, reducing CO2 emissions.
Without CO2 no tomatoes
When people breathe air, the lungs extract oxygen to use as energy. When we exhale CO2 is added to the air. In plants, this process is exactly reversed. Plants absorb CO2 and convert it under the influence of light, water and sugars into oxygen.
A major source of CO2 is OCAP. This consortium has a pipe network installed to offer (the waste) CO2 to growers like Duijvestijn. This CO2 is originated at a Shell refinery, it used to be relesed into the air though a chimney. For some time, this CO2 is no longer released into the environment, but is being used by the greenhouses. Duijvestijn Tomaten is proud to use this CO2 to grow even more sustainable.