Calcium is a climate hero
Recent research from Babes-Bolyai University [46.8°N, 23.6°E] is putting this humble mineral in the spotlight, offering fresh hope for clean, affordable, and round-the-clock renewable energy.
The study unveils a cutting-edge concept: a solar-based power plant that uses a chemical process called Calcium Looping to store and release energy. The plant doesn’t just produce electricity from sunshine — it can keep the lights on even when the sun goes down. This could be a game-changer for energy security, especially for countries in the Global North looking to reduce reliance on fossil fuels.
From Sunshine to Stone to Steam
At the heart of this innovation is a key reaction: when calcium oxide (CaO) reacts with carbon dioxide (CO2), it forms calcium carbonate (CaCO3) and releases a burst of heat. Reversing the process — breaking the CaCO3 back into CaO and CO2 — requires heat, which the plant gets from solar power. This heat can be stored chemically and released later, even at night, to generate electricity.
In other words: sun hits mirrors, mirrors heat limestone, and limestone becomes a powerful, renewable battery.
Why Should You Care?
This technology holds tantalising promise. Current energy storage options like lithium-ion batteries are expensive, resource-intensive, and not great for large-scale storage. But limestone? It’s cheap, abundant, and non-toxic. In fact, it costs about 20 €/t compared to 900 €/t for molten salts, the current favourite in solar energy storage.
More importantly, the system’s energy efficiency tops 42.5%, and its carbon footprint is just 38 kg CO2 per MWh of electricity — vastly lower than traditional power plants, which range between 100 and 500 kg. The levelised cost of electricity? A competitive 76 €/MWh (about £65).
Local Ideas, Global Gains
The plant design also cleverly splits its workday. For eight hours, solar power runs the show, charging up calcium and CO2 for storage. For the other sixteen hours, the stored materials quietly generate power on their own. It’s a 24-hour clean energy cycle that works with nature rather than against it.
Better still, the technology could be scaled up to decarbonise heavy industries like cement, steel, and chemical production. And unlike traditional carbon capture systems, this one stores the heat — not the gas — making it simpler, cheaper, and less prone to future regulatory hurdles.
A Path Forward
So what can communities and policy-makers in Northern Europe and Canada do?
- Support research into calcium looping and other thermochemical storage methods.
- Promote pilot projects that test this technology in industrial zones and sunny regions.
- Prioritise circular materials like limestone over rare metals in energy policy.
This Romanian breakthrough offers not just a peek into the future but a practical path towards it.
Source
Solar-based calcium looping power plant with thermo-chemical energy storage capability: A techno-economic and environmental (LCA) analysis, Renewable Energy, 2025-05-09
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