Interview: Sven Kerremans (Laborelec)

Before developing the electrical network of the Princess Elisabeth Station, Laborelec had already worked on the electrical systems of several big industrial sites and hospitals in Belgium and elsewhere. In what respect is the station's network different from other networks Laborelec has developed in the past?

Although the technologies we used were not new (PV solar panels, wind turbines), they had never been connected to a "zero emission" network, which can carry ten times the load of what the station's total energy production amounts to! This is the most innovative component of the network. We had to modify certain parameters and algorithms in the conception process of the basic device in order to develop a "demand side management system" capable of managing the network as a whole. It was then up to Jean [Chalon] from Schneider Electric to translate our algorithms into a machine language (a language that the Programmable Logic Controller running the electrical system recognizes).

In the standard algorithms we have developed so far, electrical grids can handle three times the load of what the total energy production amounts to. If you take into account the fact that it is statistically unrealistic to have all the electrical devices attached to the network consuming energy at 100% capacity all at the same time, the network can be brought to equilibrium with a ratio of 1:3 between production and electrical load (at a given time).

What is unique about the station's grid is that the ratio has gone up to 1:10 between production and electrical load. This would not have been possible with a conventional network management system; we had to develop a much more efficient system. This is why we worked on an algorithm that either accepts or rejects various electricity-consuming devices (when someone asks for energy to use them), based on such variables as the time of the day or the priority level of each device. This "trigger" can be reevaluated in certain emergency situations such as, for example, a medical emergency, a fire, etc. In developing our algorithms, we also had to take into account the various emergencies one could encounter.

Did working on this project in Antarctica engender any specific technical complications? What are some of the challenges you had to overcome on-site?

We encountered our first difficulty concerning the "zero emission" energy sources of the station during the pre-study phase. The energy produced by renewable energy sources varies over time. In order to avoid situations in which not enough energy is produced to run the station, it had to be possible to stock up on energy reserves and to use these reserves when energy production was low. However, the energy set aside as reserve reduces the amount of energy available for immediate use by electricity- consuming devices. The difficult part was determining the portion of energy produced that should be set aside as reserve and the portion that should be left available for immediate use.

We then also had to manage the portion of electricity available for use by the electrical consuming devices. The network accepts a different load amount depending on the reserves and available production. Also, the network's electrical load varies over time according to the priorities at certain moments of the day.

With regards to the mission you were committed to carry out on site, did you reach your objectives?

I can even say that we did more than what we were sent there for!

My thought was that if we managed to integrate and connect all of the equipment that allowed energy distribution across the network, we would be happy. In the end, we even tested and brought part of the grid into operation. This allowed us to conduct functional tests on the micro-grid and bioreactors without having to resort to using diesel fuel... So, yes, I believe we got some great work done down there.

Did you have any trouble at all adapting to the Antarctic climate?

Although the work there was very tiring, I didn't find it particularly difficult to adapt to the environment, even with the permanent daylight. It is only when I got home to Belgium that I realized how exhausted I was from the trip.

In Antarctica, we had a certain rhythm and we didn't really feel the work load that had accumulated, even during the week prior to the station's inauguration when we worked day and night racing against the clock. But we made it and the end result is just amazing!

What was the highlight of your stay?

We only had 60 days to install all of the equipment inside the station. In Belgium, under normal working conditions, it would have taken half a year to get the same work done!

Just one week before the inauguration, we still had the 14 tons of batteries to install inside the technical core of the station. In teams of four, we each carried a 74 kg battery into the station. It was dangerous because we had to be careful not to drop one: it could have caused a short circuit or the battery to explode. So we worked on the battery integration when there was nobody else around (during dinner time or in the evenings). Once we had gathered all of the batteries inside the station, we began connecting them. It was the last thing we had left to do before the official inauguration date... That night, we started up the micro-grid and worked until 4 am. Thanks to everyone lending a free hand here and there, it is no wonder we succeeded!

I imagine there is still some final work that needs to be done on site. What will Laborelec's mission next season consist of?

We have just been asked to return to Antarctica next year, probably for a 2-month mission at the end of the season when all of the wiring (power, control and data) has been completed and the grid is ready for the last phase of tests.

After we resolve the problem of synchronization between the micro-grid and the emergency generators, the next big operation will consist of moving from a micro-grid to a smart-grid that is capable of managing all of the technologies involved. Before moving into the final operational stage of the smart-grid, we will have to carry out several functional tests and processes. The water treatment unit is the most complex unit we have to work on.

Although we have already carried out certain functional tests using the current energy production and electrical load, it is not possible yet, at this stage, to say whether the algorithm works correctly. We will have a clear idea of the grid's stability once all of the energy production sources and energy consuming devices have been completely interconnected.