The Dutch greenhouse horticulture sector wants to become fossil-free, but how can this be achieved without creating new environmental problems? Siu Yin, a student of Industrial Ecology at Delft University of Technology and Leiden University, participated in the LDE Thesis Lab 'Sustainable Energy in Horticulture'. As a young researcher, he likes to look at the whole picture. ‘That's why it's so great to participate in the Lab: I get ideas that I would never have come up with myself.'
What was your research about?
For my thesis, I am participating in a project at the Thesis Lab of LDE, a collaboration between the universities of Leiden, Delft, and Rotterdam. Within the project ‘Sustainable Energy in Horticulture,’ I investigate how Dutch greenhouse horticulture can switch from gas-fired systems to fossil-free fuels with the goal of becoming climate neutral. I focus not only on CO₂ emissions but also on resource use outside the usual supply chain. After all, we extract materials with heavy machinery that runs on diesel. The question is whether this is truly sustainable. When you consider that the energy transition in the Netherlands would require as much lithium as is mined worldwide in one year, it is questionable whether this solution is both feasible and responsible.
Why is this important?
This research is important because the system we work with is far more complex than it first appears. Growers want to become fossil-free, but plants need CO₂ to grow, and that CO₂ currently comes from burning natural gas. Plants do not absorb all of that CO₂, and much of it is released when greenhouses are ventilated to reduce excess humidity. Growers sometimes even buy CO₂ from others, but that entire process often falls outside the calculation. It belongs to the indirect impact – the so-called scope 3 – which is usually not included. Growers often only look at scope 1 and 2, the emissions a company directly produces. A broader perspective is therefore essential.
How is the research conducted?
To make everything transparent, I use a Life Cycle Assessment (LCA), an accounting method to calculate the environmental impact of a product or process from start to finish. Just like in financial accounting, you can also perform greenwashing or manipulate figures. Here, greenwashing means presenting yourself as more sustainable than you actually are. My goal is to find a form of honest accounting, a middle ground in which all aspects are included. It is important that I talk to many different people and parties to gain as complete a picture as possible of all choices and scenarios.
What did you enjoy most about your research?
The most enjoyable part of my research is that it constantly surprises me. At first, everything seemed logical and clear, but over time I found that some assumptions were completely wrong. For example, I did not expect that the sector would score so poorly on certain sustainability goals. Those kinds of insights make the research interesting.
