The disruptive energy storage technology, power-to-gas, provides an opportunity for electrolyser manufacturers to increase their production capacity dramatically. In the BioCat project, electrolysis is used in the process of converting excess electrical energy from renewable energy sources to hydrogen – an application that gives way for new market opportunities.
The aim of the BioCat project is to design, engineer, construct and test a commercial-scale power-to-gas wastewater treatment plant in Denmark and demonstrate its capability to provide energy storage services to the Danish energy system. The power-to-gas approach demonstrated in the project is innovative in the fact that it uses an advanced biocatalytic system for the conversion of hydrogen and carbon dioxide to methane, the principal component of natural gas. This technology allows wind and solar energy to be stored indefinitely in existing natural gas pipelines.
Electrolysis is an important component in this energy storage solution, as it is the only technology that is able to convert excess electrical energy into hydrogen – which in turn is converted into renewable natural gas in the methanation process. The renewable natural gas can then be stored or transported in the existing gas grid. Later on, the stored energy can be discharged where and when it is needed the most, resulting in a higher overall integrated system efficiency. Consequently, the need for electrolysis systems that fit the power-to-gas solution rises concurrently with the emerging power-to-gas market.
The company Hydrogenics is an exclusive BioCat partner from the electrolysis industry, and they see great potential in the project technology- both in terms of developing a new electrolysis system that fits the power-to-gas market and in terms of being part of developing a new commercial market for the application of electrolysis.
The BioCat project is a unique opportunity for Hydrogenics to participate in the first MW-scale power-to-gas demonstrator in Denmark. Here, we have the opportunity to better understand where the electrolysis technology needs to progress further, and which regulatory support we need to move towards commercial viability, says Filip Smeets, Hydrogenics’ General Manager for On-site Generation.
Besides improving existing technology, the BioCat project makes it possible for Hydrogenics to contribute to the development of a new commercial market for electrolysers, which Filip Smeets elaborates in the following:
Hydrogenics sees the further development of the power-to-gas market as vital, which is why large scale demonstration of different technologies with state-of-the-art execution is of key importance. Here, we have the opportunity to demonstrate that the system and the technology work at a large scale, which is a necessary step towards developing a commercial market for a new application of electrolysis.
New demands for electrolysis systems
Until very recently, the electrolysis market was characterized by industrial buyers with interest in small-scale systems (approximately 300 kW or smaller) whereas the power-to-gas market demands for lower costs and large-scale systems, which possess both challenges and opportunities for the electrolysis industry.
Large electrolysers have been around for quite some time and do not pose insurmountable technological hurdles. However, in the emerging power-to-gas market, the cost of the technology needs to be kept as low as possible. The challenge therefore consists in limiting the total cost of ownership, focusing on component selection as well as on in-house construction and testing to limit on-site costs, says Filip Smeets.
Electrolysers for energy storage applications are run differently than those used in industry. In particular, electrolysers in power-to-gas applications will be ramped much more frequently and experience more turn-on/shut-down cycles. This poses challenges for system operations and materials longevity. Therefore, Hydrogenics is using the BioCat project to adapt their currently available, proven technology to better suit the operating envelope of power-to-gas. Currently, Hydrogenics is developing the latest version of a large-scale electrolysis unit, which will be used in the BioCat project. The unit discerns itself from previous generations because of its more efficient power conditioning and control system as well as its small footprint, which Filip Smeets, Hydrogenics’ General Manager for On-site Generation explains in the following:
The new system, constructed by Hydrogenics, is designed to offer a significantly improved cost per unit of hydrogen produced, and it incorporates proprietary power management technology to improve responsiveness and robustness. In addition, the power conditioning is done with a newly developed type of transformer to minimize the stress on the grid at large capacities. The new electrolyser will prove to be state-of-the-art in all these fields, while its cost will remain within the budget.
About the BioCat project
The overall objective of the BioCat Project is to design, engineer, construct and test a commercial-scale power-to-gas facility at a wastewater treatment plant in Denmark and demonstrate its capability to provide energy storage services to the Danish energy system. The project, which is funded by ForskEL, brings together some of Europe’s foremost leaders in the field of low-carbon energy systems to demonstrate the technical and economic potential of a cutting-edge energy storage technology. More information is available at www.biocat-project.com.
About the power-to-gas technology
Power-to-Gas (P2G) is an innovative approach to energy storage. By converting electrical energy to chemical energy in the form of methane, the vast existing natural gas infrastructure can be leveraged for storage and transportation of renewable energy.
About the electrolysis technology
The BioCat Project uses an advanced version of Hydrogenics’ S1000 alkaline electrolyser. The electrolyser is connected to the local power grid and draws electricity in times of low electricity prices – an indication of a supply/demand imbalance. In four different cell stacks, the electricity splits water into its molecular components hydrogen and oxygen. Both gases are immediately separated and leave the electrolyser in separate pipes. The hydrogen is then delivered to the methanation reactor, while the oxygen is supplied to the activated sludge basins for wastewater treatment.