Reduction in CO2 emissions
The signatories to the Paris Climate Agreements have agreed to reduce CO2 emissions. The horticultural sector has agreed with government to participate in this endeavour. Geothermal energy is a clean, sustainable and reliable alternative to natural gas.
Advantages of geothermal heat:
• It is a sustainable source of energy with a very low carbon footprint.
• The costs for geothermal energy remain stable and predictable for a longer amount of time.
• Unlike many other types of renewable energy, geothermal energy is not impacted by external factors (wind, sunlight, etc.).
It is available 24/7.
• Once the wells have been drilled, there is virtually no odour nuisance, dust exposure, noise exposure or visual intrusion for the environment.
Deep inside the earth it is very hot. The deeper we go, the hotter it gets. The temperature rises by approximately 33˚C for every kilometre you go down. Part of the rocks in the upper kilometres of the earth’s crust is porous and filled with water. At a depth of two to three kilometres we find water with temperatures between 70 to 100 ˚C. The energy in this hot water is called ‘geothermal heat’ or ‘geothermal energy’. This heat can be used for heating homes, buildings, industry or horticultural greenhouses.
How does geothermal heat work?
To extract the heat from the ground, we drilled three deep wells (a triblet)at our location at Nieuwlandsweg 1 to a depth of 1850 metres. One of the wells pumps the hot water upwards. A heat exchanger transfers the heat to our own fresh water system. The cooled water is returned to the same deep earth layer via the closed salt water system. The heat obtained is transferred through a hot water supply grid to heat our greenhouses.
Above ground, the wells are placed several metres away from each other but underground the end of this well is located approximately 1,5 to 2 kilometres from the first well to avoid cooling the hot water source or reservoir. The water in the earth is gradually warmed up again by heat from the earth’s crust flowing towards the earth’s surface.
Currently (2019), the Netherlands has approximately 20 geothermal doublets in production that mainly supply heat to the greenhouse horticultural sector.
Facts about Hoogweg’s geothermal heat
Did you know that:
• We drilled 3 wells (1 production well and 2 injection wells) to a depth of approx. 1800 metres.
• The pipe lengths are approx. 2200 metres.
• The production is +/- 350 m3 water per hour
• This is sufficient to heat approx. 15,000 homes.
• The water temperature is +/- 78 degrees ℃
• The water temperature when it is being pumped back is ca. 15-20 degrees ℃
• The water reservoir will provide heat for +/- 30 years