by/par Pall Arnason, IceTec, coordinator of the REVEAL project
Dans ce partenariat spécial, l’équipe AL13 est fébrile de pouvoir lancer cette première collaboration d’articles avec l’organisation islandaise Teaknisetur. L’équipe du CQRDA a eu l’occasion de rencontrer et de tisser une relation collaborative avec les membres de la délégation islandaise dans le cadre du projet Horizon Europe, lors de leur passage en région à l’automne 2025.
Le présent texte a été rédigé et vous est présenté en anglais. Un résumé en français est disponible et fait la synthèse des résultats de la recherche réalisés dans le cadre du projet REVEAL.
[FR] Résumé : L’aluminium est un excellent moyen de stockage d’énergie, dont la densité énergétique volumétrique est bien supérieure à celle des solutions de stockage telles que le méthane, l’hydrogène ou les batteries. De plus, l’aluminium est facile à transporter et à stocker, ne subit aucune perte pendant le stockage et n’est pas sujet aux incendies ou aux explosions. Il s’agit d’une solution très prometteuse pour relever le défi du stockage de l’énergie renouvelable de l’été à l’hiver, période pendant laquelle les besoins en énergie pour le chauffage des locaux sont importants. Le projet de recherche REVEAL, fruit d’une coopération entre neuf entreprises européennes, développe un cycle de stockage d’énergie en aluminium durable et rentable pour cette application. L’énergie renouvelable est utilisée pour la fusion de l’aluminium sans émissions de carbone, le combustible en aluminium réagit avec l’eau pour fournir de la chaleur et de l’électricité, et les déchets sont ensuite recyclés en alumine de qualité métallurgique. Un prototype de ce système a été développé et validé avec succès.
[ENG] Abstract: Aluminium is an excellent energy storage media, volumetric energy density is much higher than in storage solutions like methane, hydrogen or batteries. Furthermore, aluminium is easy to transport and store, no loss during storage and is not subject to fire or explosion. For the challenge to store renewable energy from summer to wintertime when much energy is needed for space heating, it is a very promising solution. The research project REVEAL, a cooperation between nine European companies, is developing a sustainable and cost-effective aluminium energy storing cycle for that application. Renewable energy is used for carbon-free aluminium smelting, the aluminium fuel reacted with water to provide heat and electricity and the waste then recycled to a smelter grade alumina. A prototype of such system has been developed and successfully validated.
It is well known that much energy is needed to produce aluminium. Much energy is also revealed when aluminium is reacted with water. This makes aluminium excellent for energy storage. The volumetric energy density is higher than for coal and oil and very high compared to other energy storage solutions, 23,500 MWh/m3 while it is only 7,700 for methane, 2,450 for hydrogen and less than 800 for batteries. In addition to that, aluminium is easy to transport and store, no loss during storage and is not subject to fire or explosion.
Interest is clearly increasing; the first conference on renewable metal fuel was held in Europe three years ago and now three conferences have been held, the two first with main focus on iron and the latest focusing on aluminium fuel.
One of the challenges in Europe´s route towards renewable energy systems is to store renewable energy for the wintertime where much energy is needed for space heating. That is also the scope of the research project REVEAL where renewable energy is used for carbon-free aluminium granule production in Iceland and the energy released as heat and electricity in Switzerland. An aluminium storage cycle is being developed. The cycle has four main steps:
- Renewable electricity is used for aluminium production in an energy efficient carbon-free smelting process (inert anodes).
- The aluminium is granulated to form fast reacting (still non-explosive) particles in a cost-effective process. That is the fuel.
- The fuel is reacted with water (< 100 °C) to release energy in form of hydrogen and heat. The hydrogen is then converted to electricity and heat.
- The material cycle is closed by calcinating the aluminium hydroxide waste to a smelter grade alumina, raw material for step 1.
Figure: Supply of renewable energy through an aluminium storage cycle.
The Icelandic partners IceTec and Arctus have been developing aluminium smelting technology for some time in cooperation with several European companies, such as Europe’s largest smelter, Trimet. It is based on vertical metal anodes and ceramic cathodes, somewhat similar to the technology the Canadien Elysis is developing. The aluminium used in the project comes from a pilot smelting cell at IceTec.
Making a good fuel from this aluminium has been a challenge. The literature available on Al/water reactions does normally show use of aluminium alloys with magnesium, gallium or other metals enhancing reactivity, but this makes the recycling step of the oxide or hydroxide more complicated and costly. In REVEAL, we have worked on a low-cost non-alloying fuel concept.
For the Al-to-Energy step we have worked on two different processes. NIC in Slovenia worked on a high temperature process, reacting with supercritical water, similar to a process developed at McGill University in Montreal. OST University in Switzerland has worked on a low temperature process. After reviewing both processes it was decided to scale up the low temperature one, it is regarded to be much safer in installation and operation as small household units. A 4 kW prototype, large enough for a normal household, was constructed for that purpose. A recycling process for waste from both these processes is being developed by SINTEF in Norway.
This aluminium storage cycle has now been successfully validated in laboratories, ready to be adapted to operation in real life conditions. Though the partners in this project have mainly foreseen it for Centre/East European cold winter application, but it could also fit well for other applications like Canadian wintertime and off-grid renewable energy supply for remote communities in Canada.
REVEAL is a cooperation of nine research centres and companies in seven European countries, funded by the European Union and Swiss authorities through the Horizon R&D framework programme. Further development is expected to be funded through this programme, a European programme where Canadian partners are also eligible for participation and funding.
The REVEAL consortium will hold a workshop in Iceland on 15 January. The programme includes presentations on the REVEAL concept, recent developments in inert anode aluminium smelting and Alu-to-Energy conversion, possible markets for aluminium-based energy storage, and life-cycle assessment of both the storage cycle and inert-anode smelting. The workshop will be in open streaming for two hours at breakfast time for those logging in from Quebec (8-10am Quebec time). For registration to streaming of the workshop: Aluminium fuel for winter heating and light
The President of Iceland visiting IceTec´s carbon-free aluminium development laboratory. From left, Gudbjörg Óskarsdóttir, CEO of IceTec, Björn Skúlason, the presedent´s husband, Halla Tómasdóttir, President of Iceland and Jón Magnússon, CEO of Arctus aluminium.
For more information on the REVEAL project: https://www.reveal-storage.eu
Authour: Pall Arnason, IceTec, coordinator of the REVEAL project (pall@icetec.is)
