The latest adventure of Aqua Battery at The Green Village

Interview met Blue Battery’s Juan Sebastián Álvarez

  • energiesysteem

The latest adventure of Aqua Battery at The Green Village

Aqua Battery has been at The Green Village since 2017, when it was just the office, Prêt-à-Loger, three innovations and project manager Willy Spanjer. They’ve seen projects come and go while continuously working on their Blue Battery in their iconic building. During these years they’ve worked on various projects, with many different parties, ranging from start-ups to government bodies, while making use of the smart grid, The Green Village and our network. An interview with Aqua Battery’s Juan Sebastián Álvarez – Project Manager Blue Battery Microgrid & Senior R&D Engineer – tells us more about the four-year-long adventure at The Green Village and their latest project on the microgrid.

In order to recap how the Blue Battery ended up at The Green Village in the first place, it’s time to take a trip down memory lane. Aqua Battery started as a spin-off from Wetsus, the European Centre of Excellence for Sustainable Water Technology, when the blue battery was still a novel topic. “When you have a research proposal and want to take it to the next level, they offer different kick-off programmes to start your own project or company. This is how Aqua Battery was founded”, according to Álvarez. Looking for partners and a pilot location to test their first project, which was still on a lab scale, they came across The Green Village back in 2017.

Initial project on Blue Battery
When asked to explain how the initial Blue Battery works, Álvarez comes fully prepared with two cups and a plastic sheet in his hands to create a visual of the process: “Imagine one cup full of fresh water, while the other contains salt water. If I mix them in a third cup, it generates energy. But you need something to harvest the energy, which is what Blue Battery aims to do. We mix the water in a stack of membranes, where the two variants of water are on opposite sides. When you apply current, the ions cross the membrane back and forth, harvesting the energy and transforming it into electric current. The energy is based on the amount of salt added.”

It seemed like such a waste to build a successful proof of concept and not take it further by connecting it to an electrical system.”

Latest project on the microgrid
The many lessons learnt from this first project sparked the urge to keep going: “It seemed like such a waste to build a successful proof of concept and not take it further by connecting it to an electrical system.” The next natural step would be to see what else the Blue Battery could achieve, which motivated the team to find partners and additional subsidies for yet another project at The Green Village. This second and latest project is a collaboration with the Hydrogen Car: A Sustainable and Local Electricity Storage in Microgrid. The goal was to demonstrate and monitor how the Blue Battery and Hydrogen Car interact in a microgrid environment.

The idea behind this project is that the two components can complement one another. The Blue Battery offers energy storage and discharge over a longer period of time, while the Hydrogen Car on the other hand releases energy quickly in short bursts. “So for example, if you’re in a house and you want to use the kettle or the washing machine, you create spikes in the consumption of energy. The Blue Battery cannot react to this, because it needs time to start the process, but the car can. Yet if you’re watching TV or charging your laptop, the Blue Battery can deliver energy because it’s stable and lasts for a longer period of time.” Besides the interaction between the two, the system surrounding it was also a focal point. How do consumption and production affect the two parts, but also: how do you make a system which understands the needs based on consumption and production?

Álvarez explains: “Within a microgrid, all the components communicate in a bi-directional way and there are three vitals steps: energy production, storage and consumption. As the three elements are controlled by a local communication device which allows bi-directional communication, the grid structure is decentralised.” It was at this point that it became clear that external parties were required to make this project a success, so Aqua Battery took the lead in a consortium. They were in contact with a former employee of Alliander who had recently set up a small company called Zown, a grid operator company. They had all the systems to integrate the individual components into a microgrid. Working with the Hydrogen Car meant collaborating with the TU Delft, where some professors also worked for Aqua Battery already.

“This project is therefore unique in the sense that the chain of production, storage and consumption is completely sustainable and renewable.”

So storage was taken care of, but production and consumption weren’t yet covered. This is where The Green Village came in: “They offered solar panels on the DC Office, an energy-consuming inhabited house and a terrain with an existing state-of-the-art infrastructure and technologies to facilitate all types of testing. This project is therefore unique in the sense that the chain of production, storage and consumption is completely sustainable – with the sole use of water, salt and hydrogen – and renewable, due to the solar panels. On top of that, it’s also placed in Prêt-à-Loger which is built in a renewable and sustainable way. Not only was the Blue Battery novel with the initial testing, this second project is unique in the Netherlands and possibly in Europe.”

But just like any research, new challenges can arise at any point during the process. Together with Firan (infra-specialist of Alliander) they worked on the business analysis to answer questions like: what is the current legislation on microgrids in the Netherlands and where could it be placed and work? Is it possible to create this new system? “In order to take this project to the next level, a theoretical model was built and placed in a software programme. From here, we tried to simulate data in order to see profiles and to compare the theoretical model to the experimental model in the near future. The model is based on theory, but does however show a good estimate of energy profiles of what we’ve seen at the microgrid project.” If you want to make optimal use of a Blue Battery, it’s best to be reasonably close to a solar or wind park, where energy is produced in a stable way. As more wind parks are popping up, there are more locations for the Blue Battery to work well.

Far away from home
While all of this is taking place during the coldest winter in the Netherlands, Álvarez and his colleagues are spending their time working on another European project on a remote Italian Island called Pantelleria: “It’s a beautiful place but getting there is something different!” Together with partners from all around Europe, they’re working on the final phase of the Horizons 2020 BAoBaB project related to a demonstration pilot for the Blue Acid/Base Battery – an upgraded version of the Blue Battery, as it’s twice as powerful but much smaller. These are exciting times in the Mediterranean as they’re currently collecting data to build a report for the European Commission. Luckily for us, Aqua Battery also has more ideas in the pipeline to start at The Green Village. Álvarez explains: “At the moment we’re thinking of connecting the Blue Battery to the DC-grid present at The Green Village. This could be interesting for us because of the reduction in energy loss due to less conversion.”

Getting your hands dirty at The Green Village
During all of these adventures, collaboration with The Green Village has always been strong. Although there will always be hurdles down the road, Álvarez perceives it as a unique environment to network and where everyone works hard: “I remember when we first arrived that there was an innovation on the WaterStraat and I met the owners of the company. They were working on the project themselves, getting their hands dirty. You could hire someone to do it, but they wanted to do it themselves, which really demonstrated something.” Not long after, in December of that year, Aqua Battery experienced their first event at The Green Village. Álvarez elaborates: They asked me to present the Blue Battery. It was a very exciting moment for me to be able to elaborate on the first world-wide Blue Battery on a pilot scale, and also the moment I connected with interesting contacts who I wouldn’t have met so easily otherwise.”

Working in a team is like clockwork
Throughout the interview it becomes abundantly clear that teamwork is incredibly important to Álvarez. The Blue Battery would not have existed without the entire team behind Aqua Battery, or the many partners they’ve worked with over the years, such as REDstack, Zown, Firan, Dot Robot and various parties within the TU Delft. Speaking highly of all of them, Álvarez notes how important it is to use differences to your advantage: “We might have different perspectives, but that only brings out the best out of everyone which you can then combine in the project. Nobody gets left behind, it’s like clockwork: everyone is essential.”

When asked about his fondest moments at The Green Village, Álvarez stresses once more how the best times were when they managed to get work done as a team. He first mentioned feeling like they’d run a marathon when realising their first project back in November 2017. That feeling of success after months of hard work recurred in August 2020 when the inauguration of the microgrid project took place: “This was such a milestone, when we got the system working. It was all online, we pressed the button and everything started to work.”

Since this precious moment, the microgrid project has come to an end, but Aqua Battery’s time at The Green Village will continue! Álvarez and his colleagues are working on a final report to summarise their findings, which will be published soon. Fortunately, it’s not a good bye, but an until next time!

By Caitlin Eagles

Photos from 2017.

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