Turbulent water turbines: one-and-a-half metres difference in height is enough to generate energy.

An increasing number of companies and organisations are endorsing the demand for sustainability. One of them is Turbulent, a young engineering company from Wilsele. They developed a small hydroelectric turbine that converts energy from rivers into electricity using whirlpools. We spoke to co-founder and CTO Geert Slachtmuylders about his passion for rivers and sustainable innovation.

How did Turbulent come about? 

“Actually, Turbulent originated from my research thesis. I was studying how a whirlpool or vortex is created in nature and how you can generate energy with it. During the Cleantech Challenge, I met the current CEO, Jasper Verreydt, with whom I founded Turbulent in 2015. But in fact, I was already working on the theory.

Turbulent also originated from my fascination with water and rivers, though. I love to walk along a river and see what the current is doing. A whirlpool is, so to speak, a piece of ‘natural design’. I think it's terrible that whole rivers and ecosystems are being destroyed by our current water management with weirs and dams. If a river stops flowing, it dies. 

As an engineer, I'm always looking for new possibilities in technology, in my case hydropower technology, and this completes the circle. At Turbulent, we develop, test and validate our water turbines. Our team currently has 14 employees. For the production of our turbines, we rely on a network of professional partners in Flanders.”

What is your vision?

“Our water turbines can help save the planet by providing clean, reliable electricity in a cost-efficient way. Moreover, we're convinced that we're creating new opportunities for isolated rural communities. Turbulent can help the development of these remote areas and the local economy. Actually, we want to help people all over the world, especially in hard-to-reach areas, to generate sustainable energy. 

Did you know that a lot of villages, even in remote regions, are on the waterfront? It's not exactly rocket science to offer hydropower as a solution here instead of, for example, a polluting diesel generator. In a village like Long Busang in the jungle of Borneo, a hydropower plant with a small storage capacity to cope with the peaks is the perfect solution. In places like that, where there's no electricity grid yet, we can connect the houses directly to our mini hydropower plant. With one turbine, we can supply forty to one hundred households with electricity, although the exact number depends on the amount of electricity they actually need.

Another advantage of these small water turbines is that the energy is continuously generated by the water chamber and is not dependent on changing parameters, such as wind or sun. So less storage is needed by batteries, meaning you can divide the maintenance costs over 10 years by 3 compared to solar panels, for example.”

Can you briefly explain how your turbines work?

“From a height difference of 1.5m, you can generate power with a whirlpool. We build a branch-way of several metres next to the watercourse. We draw the whirlpool into a spiral-shaped basin at the end of that bypass. Through a screw in the middle, the rotation is converted into energy and then current. The smallest 15-kilowatt turbine provides enough power for about 30 European households, while our largest with a capacity of 100 kilowatts can produce electricity for 200 households.”

How are they different from other water turbines?

“Our turbines use small height differences in watercourses – waterfalls or locks – to generate energy. They only need a small drop (1.5m). The speed of the water is increased by a whirlpool, which generates electricity.” In fact, our turbines are not at all like the image many people have of them. They're better compared to a slow-spinning water wheel. This design also ensures that all aquatic life can pass through the turbine fit and well.

When did you bring your turbines to market?

“We installed our first prototype in Tielt-Winge in 2016. Via Start-up Chile and FIT (Flanders Investment & Trade), we then got into Chile later that year. Chile was an excellent testing market for our product, where we could also install our first 15kW industrial prototype. From then on we scaled up, made our solution more commercial and in 2019 we installed the first commercial turbine in Bali for the Green School. Our plan was to enter into more international partnerships in 2020, but unfortunately corona put a stop to this. As a result, the growth we had hoped for this year was considerably slowed down. In the meantime, in Europe, we're working on a few projects in Portugal, France and Italy.”

Who are your customers?

“Our hydropower plant makes a community in a remote location – a village, a business park or industrial estate, plantation or production site – completely self-sufficient in electricity. Our primary target group is business leaders, plant managers and local authorities. But collaboration with development organisations, energy providers and utility companies is something we'll also consider. 

We are often the last-resort solution. The client does not receive a permit for the standard hydro solution or the population is resisting a design with a dam that puts an entire area under water, for example. This brings us into the picture: our turbine has a lower cost price and no impact on the ecological system. For most turbines, the bypass is 100m to 1km, but for our mini turbine, the river only has to be diverted over a few metres. In addition, our system is very compact: e.g. for 15kW, it's 1.20m in diameter and 1.30m in height, weighing 700kg – compared to, for example, an Archimedes screw, which has a diameter of 2m, is 5m long and weighs 2 to 3 tons.”

That sounds pretty promising! What are the obstacles you're up against?

“In Europe, that would be the legislative framework and getting permits. Remote local communities in other continents need compact and robust turbines that aren't too expensive in order to replace other unsustainable systems or simply because there's nothing in place yet. We're now focusing on these areas and working with local agents, who take care of everything related to permits. After all, it's impossible for us to delve into that for every distant country.”

Such projects in remote areas do not seem easy. Not only do you need to know the regulations and procedures to apply for permits, but also the environmental factors, etc. How do you go about this? Do you always go there yourselves? 
“That's right – working in a country like Malaysia, for example, is pretty complex. That's why collaboration with local partners is extremely important to us. Without them, we couldn't implement our projects. A local agent helps us to figure out the feasibility and to see which of our turbines ‘matches’ the needs of the customer. Every turbine we produce must be dimensioned: ‘tweaked’, so that it fits in perfectly with the location where it will be installed. That means we also need some local know-how in order to map out that location. 

For civil works, we also work with local contractors in hydraulic engineering or electricity based on the design we created along with the local agent. With our manual and training modules, they should be able to carry out the contract work and maintain the infrastructure without any problems. Before the start-up, the commissioning (the very slow start-up of the installation to check that everything is running properly, that there are no unexpected vibrations, that the turbine is generating the energy predicted, etc. - Ed.) and the testing trials in the following two days, we always go on site. After two days of testing, we turn the installation off and restart it. Once it's perfectly aligned and installed, the local contractors will take it back from us. 

We can monitor them from Belgium, but maintenance can also be carried out by the local partners. By the way, as long as they're properly maintained, they'll have an expected lifespan of thirty years.”

What has VITO done for you?

“In the product development phase, especially in the second test setup, then still at the Corda Campus in Hasselt, VITO helped us to carry out a reliable efficiency measurement. For further technology building and investments, we then built up all the capacity characteristics with varying outputs. As an external independent party, VITO measured everything and processed, cleaned up and drew conclusions from all the data. This resulted in a great deal of advice about the shape of the turbine, as well as on controlling it, speed regulation to change the water flow, which components would be ideal for the setup, how to get power to the grid, etc. VITO not only had the necessary expertise for this, but also had equipment to borrow.”

How do you see the future of Turbulent?

“Our R&D department will of course continue to develop what we've already achieved further. We're currently evolving more and more from product development to project development. In the coming years, we'll focus more on sales & marketing. We take part in trade fairs, but we're also happy that Cleantech Flanders is helping to promote us within their portfolio at foreign fairs and conferences. Along with FIT, we also went on a group business trip. 

For example, every year we already receive about 17,000 leads from all over the world, all of which we screen for feasibility. We're now focusing on those areas where we've become a necessity: developing countries that don't have access to electricity yet today, or where polluting diesel engines are still being used. During the peak of the corona pandemic, the latter even ran into problems with their electricity supply, as it happens, because diesel could not be supplied. 
So it's those regions in Central Africa and South Africa and South-East Asia (the Philippines, Malaysia, Indonesia) in particular that we focus on. There are many rivers there with an ideal drop for our turbines. In this country, there are plenty of opportunities for low-drop water power, at all the weirs, locks and old mills. But here, the regulations are so complex that the official in charge doesn't even know them anymore at times.”

Would you like to make an economic impact from sustainability as well? Would you like to innovate sustainably too? In addition to the technology and knowledge offering for (bilateral) contract work, VITO also offers specific support to SMEs and various opportunities for consortium projects (COOCK – Collective Research & Development and Collective Knowledge Dissemination and Transfer, ICON – Interdisciplinary Cooperative Research), etc., for large and small companies.