Elestor and Koninklijke Vopak N.V. are conducting a feasibility study on the application of a flow battery, a system for large-scale storage of electricity generated on the basis of hydrogen and bromine. Coupling the flow battery to the HyTransPort-network in the port of Rotterdam will eliminate the need for the storage of hydrogen, which will reduce the costs of electricity storage.

With a flow battery, the energy flows from a tank towards the cells. That’s the main difference compared to a traditional battery, in which the energy is already stored in the battery cell. Wiebrand Kout, founder and CTO of Elestor: “The advantage of a flow battery is that the energy and the capacity are detached from one another, as such the full capacity can be used accordingly.” In addition to that, the flow battery makes use of bromine (an element present in seawater) and hydrogen. There is an abundance of both these substances in the port of Rotterdam – two important reasons that allow the costs to be reduced.

Such changes in the energy system require an increase in capacity. “In collaboration with Vopak we are working on upscaling the capacity of the flow.” Vopak is specialized in large-scale storage of various liquid and gaseous products.

Existing hydrogen-pipeline

The storage of hydrogen is costly, which makes it interesting to examine different methods for storage. After all, it is not strictly necessary to store the hydrogen in one’s own battery system. “The existing hydrogen pipeline makes Rotterdam an excellent location to further roll out this innovation. The pipeline functions as a long hydrogen tank, during the loading the flow battery adds hydrogen to the pipeline, during the unloading its extracts the exact same amount of hydrogen” so explains Wiebrand. Therefore, the effect is zero: the pipeline is merely used for temporal storage which saves money and valuable space.

“This subsidy allows us to map all the (economic) conditions and the licensability of our initiative.” Currently, Elestor is researching whether the hydrogen tank is suitable for this type of storage. If there is something present in the flow battery that affects the hydrogen negatively, or the other way around, pollution could occur. After all, storage differs from the current function of the pipeline: use and consume. Also, this construction will change the revenue model of the owner, HyTransPort, which is another question Elestor is currently addressing.

This is a comprehensive project which needs a solid and proper foundation. Every innovation that springs in Rotterdam, may very well spread through Europe. “It is no coincidence that this starts in Rotterdam; the production capacity, offshore wind and electrification are very important for the port. Moreover, Vopak has its headquarters in Rotterdam.

Head start

This concept is so new, that even the owners are impressed. It diverges from anything that has been done so far. Wiebrand predicts this type of storage will become regular within five to ten years: “In the future, the technology of large-scale flow batteries will surmount into installations with a size comparable to that of chemical- and powerplants. “In that way, the initiative could provide employment in the Rotterdam region for over 500 FTE’s. And with the first large carbon neutral industrial terrains, Rotterdam has a major head start.”