Periodic Reporting for period 2 - REVEAL (Revolutionary energy storage cycle with carbon free aluminium)
Reporting period: 2023-11-01 to 2025-02-28
One of the main keys – and possibly THE main key - for a climate neutral Europe are technologies for the storage of renewable energies over longer time at an attractive cost and with an acceptable environmental impact. Renewable electricity and heat can be produced cheaply today and short-term storage solutions for evening out mismatches between production and demand are available at low cost. However, technologies for storing renewables for longer time-spans of months or seasons are scarce and costly and thus not widely used yet. Therefore, the REVEAL project develops a game-changing and unique solution to this challenge, using the conversion of aluminium oxide into aluminium metal (Power-to-Al) in an environmentally friendly way to store renewable energy and produce a "renewable fuel" in the form of aluminium. This ground-breaking technical solution will enable to store large amounts of energy with an unmatched energy storage density of over 15 MWh/m3 at an attractively low cost, without losses and with lower environmental impact than today's solutions. For example: cost for converting electricity into a seasonally storable form is expected to be less than 7 ct/kWh, and the easily transportable energy vector can be used for heat and electricity or hydrogen production wherever and whenever needed, in scalable units from few kW to the MW range. Thus, this breakthrough high-density storage solution will enable to cover energy demands flexibly also in small units and off-grid situations, and – above all – in seasons where the demand is much higher than local renewable production could possibly cover. Therefore, with the emerging technology of carbon free reduction of aluminium oxide to aluminium in combination with the release of energy from an aluminium storage vector this project will provide one of the missing pieces of the puzzle for a climate neutral Europe.
The overall objective of the REVEAL project is the development of breakthrough components and solutions that are needed for an Al electrochemical energy storage cycle that is based on renewable electricity without emissions of greenhouse gases from the Al smelter process and emission free Al-to-Energy with better economic and environmental performance.
The game-changing and unique solution of the REVEAL project is using the conversion of aluminium oxide into elementary aluminium (Power-to-Al) to store renewable energy and produce a "renewable fuel" that can be stored loss-free for any desired time. When most energy is needed and electricity prices are high, renewable Al fuel is converted to heat and electricity in order to cover low temperature heat and electricity demand of buildings, or to cover energy demand for processes by providing high temperature heat and hydrogen.
The overall objective of the REVEAL project is the development of breakthrough components and solutions that are needed for an Al electrochemical energy storage cycle that is based on renewable electricity without emissions of greenhouse gases from the Al smelter process and emission free Al-to-Energy with better economic and environmental performance.
The game-changing and unique solution of the REVEAL project is using the conversion of aluminium oxide into elementary aluminium (Power-to-Al) to store renewable energy and produce a "renewable fuel" that can be stored loss-free for any desired time. When most energy is needed and electricity prices are high, renewable Al fuel is converted to heat and electricity in order to cover low temperature heat and electricity demand of buildings, or to cover energy demand for processes by providing high temperature heat and hydrogen.
Work has been performed towards the main technical challenges. The main achievements till now are:
• A medium size cell (500A) has been developed for carbon-free smelting of aluminium based on renewable electricity and “low GWP” aluminium granules produced. Purity of the produced aluminium as well as the off-gases of the process have been analysed
• A sensor for measuring the alumina concentration in the molten electrolyte has been developed and suitability for steering the process has been assessed.
• Chemical processes have been studied for the generation of energy from Al (Alu-to-Energy)
• Simulation studies confirm that much less than 1 m3 of renewable metal fuel in the form of aluminium is sufficient to supply a common single-family home or dwelling with heat and electricity for the whole winter in a Central European, heating demand dominated climate.
• A low-temperature 4kW reactor for Al-to-Energy has been constructed.
• The first international symposium on aluminium metal fuel was held.
• A medium size cell (500A) has been developed for carbon-free smelting of aluminium based on renewable electricity and “low GWP” aluminium granules produced. Purity of the produced aluminium as well as the off-gases of the process have been analysed
• A sensor for measuring the alumina concentration in the molten electrolyte has been developed and suitability for steering the process has been assessed.
• Chemical processes have been studied for the generation of energy from Al (Alu-to-Energy)
• Simulation studies confirm that much less than 1 m3 of renewable metal fuel in the form of aluminium is sufficient to supply a common single-family home or dwelling with heat and electricity for the whole winter in a Central European, heating demand dominated climate.
• A low-temperature 4kW reactor for Al-to-Energy has been constructed.
• The first international symposium on aluminium metal fuel was held.
• The inert-anode smelting process developed shows the expected emission reductions: no CO2 generated and no CFx. Produced aluminium has similar purity as from conventional smelters
• Alumina sensor developed showed acceptable performance, as can be seen in the publication https://link.springer.com/chapter/10.1007/978-3-031-50308-5_83(opens in new window).
• Our chemical reaction studies for Al-to-Energy have shown close to 100% turnover in small scale reaction cells and vessels, both for the low-temperature and for the high-temperature route.
• Performance of different aluminium fuels is published in https://www.sciencedirect.com/science/article/pii/S0360319925012121(opens in new window) and a production process patent submitted.
• The outstanding energy density of 15 MWh/m3 for bulk aluminium granular material has been confirmed.
• A spin-of company has been formed for taking the low-temperature Al reaction technology forward into marketable products.
• Alumina sensor developed showed acceptable performance, as can be seen in the publication https://link.springer.com/chapter/10.1007/978-3-031-50308-5_83(opens in new window).
• Our chemical reaction studies for Al-to-Energy have shown close to 100% turnover in small scale reaction cells and vessels, both for the low-temperature and for the high-temperature route.
• Performance of different aluminium fuels is published in https://www.sciencedirect.com/science/article/pii/S0360319925012121(opens in new window) and a production process patent submitted.
• The outstanding energy density of 15 MWh/m3 for bulk aluminium granular material has been confirmed.
• A spin-of company has been formed for taking the low-temperature Al reaction technology forward into marketable products.