Portugal is setting a bold example in the transition to renewable energy, with a remarkable 70% of its electricity already derived from renewable sources as of 2023. Yet, as renewable generation expands, so does the challenge of managing intermittent power supply from sources like wind and solar. The latest policy brief from the National Laboratory for Energy and Geology highlights how hydrogen (H₂) storage could play a transformative role in ensuring energy stability and sustainability as Portugal moves toward full carbon neutrality.
Why Hydrogen Storage?
As Portugal ramps up its solar and wind capacity, reaching a target of 8.6 GW of renewable capacity by 2030, storing excess energy becomes essential. Hydrogen, produced through electrolysis—a process that splits water into hydrogen and oxygen using renewable electricity—offers a solution. This hydrogen can be stored and then converted back into electricity when needed, providing a flexible backup to balance energy supply with demand, especially during low-wind or cloudy days.
Innovative Storage Strategies
The briefing outlines both established and emerging hydrogen storage methods, each with distinct applications:
- Compressed Hydrogen (confusingly called CH₂): This involves storing hydrogen gas at high pressures, making it practical for smaller-scale applications.
- Cryogenic Storage (Liquid Hydrogen): This process involves cooling hydrogen to extremely low temperatures, reducing its volume for storage. While energy-intensive, it’s ideal for larger, long-term storage solutions.
- Salt Caverns: One of the most promising approaches, salt cavern storage involves creating large underground spaces where hydrogen can be safely stored under pressure. Portugal’s Carriço salt caverns are being adapted for hydrogen, with plans to expand storage to meet future demands.
Benefits for a Renewable Grid
The versatility of hydrogen storage allows it to serve as a “power-to-X” energy carrier, meaning it can convert renewable electricity into hydrogen that can be used directly, stored, or transformed into other fuels (e.g., ammonia, synthetic natural gas). This flexibility supports Portugal’s ability to reduce curtailments—the need to waste surplus renewable energy when it exceeds demand—and instead, harness this energy for future use. This hydrogen can also power heavy industries, support seasonal storage needs, and even fuel transport, reducing Portugal’s reliance on imported fuels.
Policy and International Cooperation
To realise these goals, Portugal’s National Hydrogen Strategy sets out ambitious targets for integrating hydrogen into its energy mix. The strategy also aligns with REPowerEU goals, which aim to bolster Europe’s energy independence by creating a cross-border hydrogen network. As part of this vision, Portugal could become a major exporter of green hydrogen, especially to neighbouring Spain and across Europe, where demand for clean energy is rising.
A Blueprint for Sustainable Growth
Portugal’s hydrogen initiatives demonstrate a model for other countries looking to secure renewable energy futures. By investing in hydrogen storage technologies, Portugal is building a resilient, flexible energy system that not only supports a high share of renewables but also positions the country as a leader in the green hydrogen economy.
This innovative approach offers a glimpse into a future where renewable energy systems are self-sustaining, flexible, and capable of meeting the world’s energy demands without compromising the planet’s health. As Portugal continues to push the boundaries of hydrogen storage, it sets a powerful precedent for global sustainability efforts.
Source
Simões, S. G., Amorim, F., Portillo, J. C. C., Machado, S., Carvalho, J., Dias, R., Sampaio, J., Picado, A., Catarino, J., Rangel, C. M., Lopes, T., Gírio, F., Ponce de Leão, T. (2024). Hydrogen Storage in Portugal (Policy Brief October 2024). National Laboratory
for Energy and Geology
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