In the spring of 2022, our colleague Colin Debruyne left on a very special and exceptional mission to the Democratic Republic of Congo. At the request of the University Gent , the electrical engineering know-how of ATS was called upon following a breakdown of a 1,000 V cable of their climate tower located deep in the Congolese rainforest. We visited Prof. Dr. Pascal Boeckx (principal investigator), Thomas Sibret (project manager) and Lodewijk Lefevre (technical expert).
Climate tower captures information in the fight against climate change
The University Gent, more specifically the ISOFYS research group of the Faculty of Bioengineering under the leadership of Professor Dr. Pascal Boeckx, is conducting scientific research deep in the tropical forest of the Democratic Republic of Congo on the physiological functioning and uptake of CO2 by the rainforest of the Congo Basin. Based on a lot of measurement data, researchers produce predictions around CO2 uptake. Much of this data comes from the climate tower that the University of Gent installed there in 2020. Such research is an indispensable key to knowing how much CO2 is absorbed by tropical forests and is essential in the study of climate change.
A climate tower is not a new feature. There are climate towers all over the world in forests, swamps, grasslands, fields, among others... But in the Congo basin, the second largest rainforest in the world, there was none until recently. For this reason, there was a large gap in knowledge about the functioning of this rainforest with regard to the exchange of CO2 with the atmosphere.
The UGent climate tower is 55 m high and rises above the canopy of trees. At the top of the tower, sensors measure the balance between CO2 uptake and release in addition to all kinds of meteorological parameters. Through photosynthesis, a forest absorbs CO2 and releases some of it through various respiration mechanisms. The difference between uptake and release ultimately determines how much CO2 such an ecosystem absorbs. Because of the changing climate, it is important to measure this evolution and is interesting for the preparation of scientific projections. Because of the size of the Congo basin, about 3.7 million km2, this tower is essential to understand the influence of this rainforest on global atmospheric CO2 concentrations and additional climate change.
'Lightning Capital of the World'
The tower's materials were delivered from Europe. The tower was installed by Congolese contractors. The equipment itself was installed and calibrated by researchers at the University Gent . To provide electricity to the tower, a solar park with batteries was installed in a clearing 2.2 km outside the forest. Locally, the tower was also equipped with emergency solar panels.
But since the tower is set up in the "Lightning Capital of the World," the place with about 205 lightning bolts per km2 annually, things suddenly went awry in May 2021. Lightning struck it and the cable between the solar park and the tower broke. It took some time to diagnose the fault and a quick fix offered no solution. From this fact, they turned to ... ATS. BU Power Quality was commissioned to look at how the problem could be fixed. Colin Debruyne: "First support was given to select the correct cable and we looked at what would be needed in case lightning struck again. Thanks to ATS Group's industrial network, together with Stagobel and Dehn we looked at what would be needed to address this correctly and a technical implementation plan was provided."
Finally, in the spring of 2022, Colin did go on site to validate that what was technically described was correctly installed by the local technicians. The on-site intervention identified an additional problem with the transformers. These had to be tested and measured. The local electrical technicians thus received limited training by "docteur Colin," as he was called there.
Finally, the cable between the solar farm was completely reinstalled and was laid 1.3 m deep. The old cable, which is 30 cm deep, remains in place for protection in case lightning strikes again. We recently learned that lightning struck again and that the installation withstood it without any problems!
Great adventure and culture shock
Together with Louis Lefevre, the technical expert on the research team and responsible for the tower's electricity, equipment and maintenance, the expedition began. It became so much more than a weekday "customer visit. What was already considered normal for the UGent team was a real shock for newcomers. Colin: "The bustle and chaos in Kinshasa for the necessary stopover was exchanged for a three-hour inland flight to Kisangani. After the necessary formalities (and informalities) followed a two-hour boat ride on the Congo River to arrive in Yangambi. From there, another hour of travel time was added with a motorcycle taxi ride in the jungle to finally reach the flux tower. "After that, it was back to basics, with virtually no Internet and limited access to electricity and running water. Unrefrigerated beers provided a peaceful doze off in balmy temperatures, but small unwanted nocturnal visitors in the bedroom could, however, disrupt sleep. Food was provided by "Maman Angèle," with banana, fresh avocado and mango in the morning; in the afternoon the food (rice, fish, chicken, beans, goat, pig, etc.) was brought in Tupperware pots via the mototaxi. In the evening, the team ate together in the cottage of "Maman Angèle," with just one meager bulb over their heads, powered by solar energy, of course. But the fact that the Congolese people can be very hospitable was something Colin was able to experience more than once.
Are there already results of the measurements?
Professor Pascal Boeckx: "The tower has been operational since the end of 2020. It is still too early for results. But we have been keeping track of other measurements from that region for some time. For example, the temperature there has been accurately recorded every day since 1960. Over the past sixty years, it has increased by one degree. The difference between 25 and 26 C° does not seem much at first glance. However, we note that the number of extremely hot days, above 32 C° is increasing sharply. The amount of precipitation is not increasing, only it is falling more intensely than ever. So the extremes are increasing and this also has an impact on the photosynthesis of trees. The biggest concern is that this photosynthesis through the leaves is taking a huge dive and evaporation is also decreasing. Because of this, it could well be that due to the rise in temperature, the trees drop their leaves during the dry season and then the complete functioning of this ecosystem changes. To notice these evolutions is precisely why it is so crucial to conduct long-term research on this important ecosystem. The big challenge here is to get this funded for a long period of time. Fellowships are often very competitive and short in duration."