In the greenhouse horticulture sector, we need to increase our contribution to the energy transition. Although this a big challenge for many, Gebroeders Vahl – cucumber growers who have heated their greenhouses with renewable geothermal energy since 2012 – see it as an opportunity. “We can’t stay dependent on gas forever,” says Kees Vahl. “So it’s better to invest in more sustainable energy sources.”
What’s the secret behind Gebroeders Vahl?
“Perseverance. That’s really the single most important thing when you make the switch to geothermal energy. It took us years to get the correct permits and funding, as geothermal energy falls under the Dutch Mining Act. So as a grower, you have to meet the same requirements as gas and oil companies. You really need the support of local authorities in this process, otherwise you won’t make it.”
At what moment did you think things had to change?
“The idea to use an alternative energy source had been around for a while. For instance, my father and my uncle were already using a wood boiler in 2005. In 2008, gas prices shot through the roof again, which was the moment at which we decided – along with other growers in the region – to look at geothermal energy.”
“The fact that we’re a family business who has always worked with nature and plants was also an advantage. We’re aware that we can’t continually deplete the earth’s resources and we’re fortunate enough as a family to be able to invest and make decisions for the long term.”
Who was your teacher?
“I learned the most from practice, from my father Tonnie and my uncle André. As a grower, you work in an incredibly dynamic environment. Of course, you’re busy with your products, but you have to deal with all sorts of other things, like packaging, customer service and energy saving. You’re continually running a business, so you’re always learning.”
What’s the first thing you need to do if you want to cultivate without gas?
“Ensure you develop good connections with local authorities, and don’t do it alone. Several growers can use the same geothermal well, so make sure to work together. We work in a cluster arrangement ourselves, which makes it much easier to apply for permits and funding. If it’s too big an investment at present, then my advice to other growers is to start off with other energy-saving measures. Many growers are involved in ‘New Cultivation’, testing things like double screens, lower temperatures and LED lighting.”
What risks are involved in cultivation without gas?
“You generate water from the ground and that process has to be completely safe. Our geothermal well was only the fourth in the Netherlands, so we didn’t have much prior knowledge. So over the years, we had maintenance costs in order to guarantee the well’s safety. But I still see it as a good investment, as we’ve covered our energy cost for the coming fifteen years.”
“Another challenge is that geothermal energy covers around 60-70% of your heating needs. If you want to operate completely without gas as a grower, then you need to use biomass at peak times in the winter. At one of our branches, we’ve already switched to biomass. This combination is ultimately the cleanest and most sustainable solution.”
How does geothermal energy work?
Water at a temperature of over 70 degrees Celsius is pumped from a depth of 1,800 meters below the organization’s location. This is used to heat the greenhouses. When the water has cooled down, it is pumped back down to the same depth. Read more about the project that Gebroeders Vahl are involved in: https://www.greenhousegeopower.nl/
Gebroeders Vahl are partners of Grodan, located in IJsselmuiden. 80% of the cucumber grower’s produce is grown on stone wool substrates manufactured by Grodan.
This story is part of the Gro-Hacks series, in which Grodan asks partners and friends about the lessons we can learn from their innovative entrepreneurial stories.