“Green Aluminium” is relatively a modern term referred to the metal produced with significantly lower carbon footprint. This is mainly achieved through recycling or using recycled metal as input, deploying breakthrough technologies such as inert anodes and carbon capture and storage, or through the use of renewable energy sources like hydropower, solar, wind or geothermal electricity. While there is no particular global standard, but usually, aluminium with up to 4 tonnes of CO2e per tonne of metal is commonly used across the industry as a low-carbon reference. This is a cradle-to-gate measurement equivalent to GHG Protocol of Scope 1, Scope 2 and relevant upstream Scope 3 emissions from bauxite mining, alumina refining, and high energy-intensive smelting process.
Recycled and Renewable – how much is not too much
The recycled content varies across products, such as primary foundry alloy products contain close to 30 per cent of post-consumer scrap, while some products even contain 75 per cent. Scrap usage saves almost 95 per cent of energy consumption as compared to the primary aluminium production process. On average, the energy intensity of primary aluminium is around 70 GJ per tonne, making it more power-intensive than steel and cement on a per-tonne basis.
On the other hand, 100 per cent usage of renewable energy is ideal for producing true green aluminium. Switching from coal to renewables can reduce the carbon footprint of aluminium smelting process by roughly 5 times.
How old is ALuminium industry’s transition journey to renewables?
The transitioning journey to renewable energy dates back to the late-19th or 20th Century and it started with the use of hydropower. During the said period, Russia began generating electricity from the energy of moving water. From 1963 to 1971, the Bratsk HPP in Russia was the world’s largest hydroelectric power stations by installed capacity (4.5 GW). The station played a crucial role in the creation of the Bratsk-Ust-Ilimsk territorial-industrial complex, which included the Bratsk Aluminium Smelter (BrAZ).
Cut to 2025, hydropower still dominates as a major renewable energy source in the aluminium industry, accounting for 34 to 39 per cent of global energy mix used in the industry.
Interestingly, solar accounts for the highest share of renewable energy capacity across the globe, yet it is hydropower that is largely being used across the world’s aluminium industry. As of 2025, global cumulative solar power capacity is 2,900 GW, while that of hydro energy is nearly 1,290 GW. Here’s the global renewable energy capacity by source (GW):
Source: https://mobilitynotes.com/irena-renewable-energy-capacity-statistics-2025/
Why hydro over solar energy – answer is here
Hydro power is a cost-competitive, long-term energy source with prices typically ranging from 2 to 4 cents per kilowatt-hour (kWh), or USD 18– USD 1,008/MWh for small-scale projects. Operational costs are also low due to reliance on water instead of fuel. . High upfront capital costs for construction range from USD 1,050 to USD 7,650 per kilowatt (kW) for large plants and up to $8,000 per kW for small projects.
The cost of electricity generated by hydropower is generally low, although site-specific. The levelised cost of electricity (LCOE) for hydropower refurbishments and upgrades ranges from as low as USD 0.01/kWh for additional capacity at an existing hydropower project to around USD 0.05/kWh for a more expensive upgrade project, assuming a 10 per cent cost of capital. The LCOE for large hydropower projects typically ranges from USD 0.02 to USD 0.19/kWh assuming a 10 per cent cost of capital. The LCOE range for small hydropower projects for a number of real-world projects in developing countries evaluated by IRENA was between USD 0.02 and USD 0.10/kWh, making small hydro a very cost-competitive option to supply electricity to the grid, or to supply off-grid rural electrification schemes. Very small hydropower projects can have higher costs than this and can have an LCOE of USD 0.27/kWh or more for pico-hydro systems.
Besides cost, hydropower with storage in reservoirs offers higher stability of the energy source. Unlike solar energy, which is intermittent and dependent on daylight, hydropower is consistent and can act as a reliable baseload power option. With large reservoirs, hydropower can store energy over weeks, months, seasons or even years. Even in relation to wind energy, hydropower is efficient as it converts about 90 per cent of water’s energy into electricity, as compared to 20 to 40 per cent of energy converted by wind turbines.
Owing to its efficiency, hydropower, until 2024, accounted for 14 per cent of the world’s renewable power generation. Electricity generated from hydropower was 4,578 TWh from installed capacity of 1,443 GW, according to the International Hydropower Association (IHA). In contrast, solar power accounted for 7 per cent. Independent research suggests the use of hydropower instead of fossil fuels for electricity generation has alone helped to avoid more than 100 billion tonnes of carbon dioxide over the past fifty years. IHA estimates that if hydro energy is replaced with coal-based power, the environment will see an additional up to 4 billion tonnes of greenhouse gas emissions annually.
To know more about the integration of renewable energy in aluminium production process as part of its decarbonisation drive, read our magazine: Sustainability & Recycling: Aluminium's Dual Commitment
Countries where hydropower is the backbone for aluminium industry
From the late 19th century to the present day, hydropower has shaped aluminium smelting, with Russia standing among the world’s key hydroelectricity producers. The first hydroelectric power plant in Russia was built in 1892 on the Berezovka River in the Rudny Altai region. In 1896, the Pavlovskaya HPP was launched in the Irkutsk Governorate. Then the project Volkhov Hydroelectric Power Station was designed under the leadership of engineer Genrikh Graftio in 1902. However, the Supreme Council of the National Economy of the RSFSR and Vladimir Lenin only became interested in the project in 1918. Later, in 1927, the station reached full capacity after being incorporated into the GOELRO electrification plan. The GOELRO Plan became the world’s first example of a comprehensive state approach to the development of the energy sector in general and hydropower in particular. It envisioned the construction of 30 power stations with a total capacity of 1.75 million kW, including 10 hydroelectric power plants.
Volkhov Hydroelectric Power Station is still in operation. It historically provided power to the Volkhov Aluminium Smelter (VAZ) in the Leningrad Oblast, Russia. The power plant and the smelter were constructed as a combined complex in 1931 to pioneer Russia's domestic aluminium industry.
The legacy of these hydropower projects continues to support Russia’s low-carbon aluminium production. Today, RUSAL, Russia’s biggest aluminium producer churns out up to 98 per cent of aluminium with Siberian hydroelectricity, emitting only 2.2 tonnes CO2-equivalent per tonne (Scope 1 & 2). RUSAL’s Taishet and Boguchansky (BoAZ) aluminium smelters in Siberia, part of En+ Group’s metals business, are positioned to produce low-carbon aluminium using hydro energy from Siberian hydroelectric power plants and RusHydro's Boguchany Dam on Angara river, respectively. Unlike older Siberian plants that are built strictly for grid power and regional development, Boguchany is uniquely tied to private industrial expansion and supplies energy directly to an adjacent aluminum smelter. Other smelters like Bratsk (BrAZ), Irkutsk, Krasnoyarsk and Sayanogorsk also benefit from Siberian hydropower and are now positioned within RUSAL’s low-carbon aluminium portfolio.
RUSAL became the first international company to receive Green Power Aluminium (GPA) certification. Specialists from the China Nonferrous Metals Industry Association (CNIA), led by Ma Congzhen, Head of the Green Product Evaluation Centre, visited and certified three of the company’s major aluminium smelters: the Krasnoyarsk and Bratsk aluminium plants, each with annual production capacity exceeding 1 million tonnes, as well as the Irkutsk aluminium plant with a capacity of 425,000 tonnes per year. All three facilities confirmed compliance with the standards established under the GPA initiative.
China, the country which is known for its reliance on coal power, also initiated a shift to hydropower, in a bid to achieve peak CO2 emissions before 2030 and carbon neutrality by 2060. From 2019 to 2024, China’s hydropower share in energy capacity grew from 10 per cent to 19.4 per cent, while coal-based energy decreased from 80 per cent to 69 per cent. By the end of 2025, China’s total installed hydropower capacity reached approximately 442 GW, while pumped storage is set to expand to 120 GW by 2030. Yunnan and Sichuan are primarily the two provinces where hydropower-based aluminium production is concentrated. About 13 million tonnes of aluminium production capacity has collectively moved to these provinces from Shandong, Henan, and Xinjiang over the past few years. Green energy is the factor, complemented by cost. In Shandong, the electricity cost per tonne of aluminium is RMB 5,400-5,700, while in Yunnan, with direct supply from hydropower, the electricity cost per tonne is as low as RMB 4,300-4,700. Hence, nearly RMB 2,000 cost savings per tonne, leading to a profit margin exceeding RMB 100 million a year.
Outside Russia and China, Canada, Brazil and Norway are the three other countries known for their hydro-powered aluminium. Canada produces 3.3 million tonnes of the metal annually, of which 96 per cent is produced with hydroelectricity. Canada’s main production hub of aluminium is based in Québec, where hydropower accounts for over 97 per cent of total net electricity production. Hydro-Québec operates one of the world’s largest hydropower systems, generated by major river systems and supported by more than 60 hydroelectric stations providing a total installed capacity of 37.2 to 37.37 GW as of late 2023. La Grande River hosts the massive James Bay project, which features the 5,616 MW Robert-Bourassa facility, and other rivers like Romaine, featuring a 1.55 GW complex, Saguenay, and Saint-Maurice support hydropower generation in Québec.
Brazil produces 80 per cent of its aluminium powered by hydroelectricity, which contributes 11.4 per cent to the country’s total energy mix. One of the key producers Hydro Albras in Barcarena, Pará, is highly dependent on hydroelectricity for its 700 MW of energy required for smelting. This power is sourced from the nearby Tucuruí Hydroelectric Plant. Norway, a well-known hub for renewable energy usage and low-carbon aluminium production, produces 100 per cent of primary aluminium with green energy, mostly hydropower sourced from its own captive power production portfolio, long-term power purchase agreements (PPAs), and strategic investments in new, upgraded infrastructure. Hydro operates 40 proprietary hydropower plants, generating 9.4 TWh of renewable electricity in a normal year.
Beyond these countries, there are several that generate or consume hydroelectricity. Paraguay generates 100 per cent of its consumed electricity from hydroelectric power, Nepal over 99 per cent, and Switzerland 60 per cent. Besides, there are Albania, Angola, Democratic Republic of Congo, Ethiopia, Mozambique, Zambia, and Iceland that considerably rely on hydro. Altogether, about 4,400 terawatt‑hours of hydroelectricity is produced per year, accounting for 15 per cent of the world’s annual electricity generation. Now, by the rule of law, primary aluminium smelting consumes 4 per cent of world electricity; so, considering 25,000–28,000 as a reasonable modern estimate of total global electricity consumption, 4 per cent of that consumed by the aluminium industry is 1,000–1,120 TWh per year. So, applying 30–40 per cent to the total energy consumption, hydroenergy supports 300- 450 TWh per year, given the sector’s mix.
To minimise this gap between consumption and capacity, smelters need to enter into long-term PPAs with hydroelectric producers, especially if the smelters are not geographically located near hydropower-rich regions. Even cross-border energy trading could be an option, or smart grid integration.
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