Solar Energy Has an Aluminum Problem
Solar is growing rapidly, but producers are running out of aluminum, a not so carbon-friendly material.
The solar industry has 2 big problems. First, aluminum is a key material in creating solar panels and the infrastructure necessary to get them up and running, but aluminum production is unlikely to keep pace with the growth of the industry. Second, mining and smelting aluminum have a huge carbon footprint, offsetting much of the benefits solar has for the environment. If we are going to stay under the 2 degrees Celsius limit detailed in the Paris Climate Agreement, we need to figure out solutions for both of these.
The Paris Agreement
The global average temperature has been steadily increasing since the dawn of the 1st Industrial Revolution, when humanity began to emit large amounts of greenhouse gases such as carbon dioxide, synthetic fluorinated gases, and methane. As the name suggests, these gases trap Earth’s heat and reflected solar radiation, causing the planet’s surface to warm. Although the Earth’s natural cycles have changed the climate numerous times in the last 800,000 years, the current trend is certainly outside the normal range and can be directly attributed to human activity.
Today, the biggest emitter of greenhouse gases is the energy industry, which encompasses the energy used in homes and buildings, industries, and transportation. Together these 3 are responsible for 73% of the global greenhouse emissions. According to the World Bank about 40% of electricity is generated by burning coal, a particularly environmentally detrimental hydrocarbon, although this has declined in recent years, due largely to the expansion of the renewable energy and natural gas sectors. The transportation industry, which includes shipping, airlines, personal cars, etc., still mostly runs on petroleum, another dirty hydrocarbon, although the electrical vehicle industry is growing steadily.
Although changes are slowly being implemented by governments, corporations, and individuals, the global community of nations decided to create a framework for fast-tracking them. On December 12th, 2015, 196 parties formally adopted the Paris Agreement as an international treaty under the auspices of the United Nations. A landmark treaty to reduce greenhouse gas emissions and mitigate the problems already caused, it was signed in April 2016, on Earth Day. It aims to make the world carbon neutral by 2050. It includes specific goals, nationally determined contributions that must demonstrate a consistent trend and be accelerated every 5 years, a proposal for a carbon trading system, financing options for developing countries, etc.
A major part of this agreement is the widespread switch to renewable energy, of which solar plays a pivotal role because it provides a much more carbon-friendly method of energy production, helping nations reduce carbon emission within the proposed timeline. According to the US National Renewable Energy Laboratory, life-cycle emissions for solar power are 40 kg of carbon dioxide per megawatt-hour, while coal’s is 1,000 kg per mega-watt hour.
The Aluminum Problems
Aluminum is amazing. Making up over 8% of the Earth’s crust, it can be found just about everywhere in the modern world because it’s corrosion resistant, has an impressive strength to weight ratio, and is virtually infinitely recyclable. But when it comes to renewable energy, there’s not enough of it, and it’s not so environmentally friendly.
A study published in Nature Sustainability found that, given the accelerating global effort to reduce greenhouse gas emissions by 2050, solar capacity will need to grow by 85 times its current amount. The researchers believe “we will need more than 60 TW of photovoltaics installed and must be producing up to 4.5 TW of additional capacity each year if we are to rapidly reduce emissions to ‘net zero’.” According to their estimates, this will account for roughly 40% of the aluminum brought to market, an amount that is widely considered to be infeasible. The situation is even worse for renewable energy when you consider the fact that aluminum is also an important material in the production of wind turbines and lithium-ion batteries in electric vehicles.
The world also needs to come to terms with the fact that aluminum production creates a lot of greenhouse gases, drastically undercutting the environmental benefits of it being used in renewable energy projects. The authors of the study from Nature Sustainability noted that in China, by far the largest aluminum producer, 14.5 tonnes of carbon dioxide are emitted per tonne of aluminum. This is largely due to the use of energy-intensive electrolysis, a process in which electricity is used to separate aluminum from ore. For the means of comparison, the steel industry’s impact is less than 2 tonnes of carbon dioxide per tonne. If the solar industry ramps up the way the authors predict, this would produce an alarming 4 gigatonnes of carbon dioxide, as well as other harmful emissions such as perfluorocarbons, sulfur hexafluoride, and hydrofluorocarbons.
The Aluminum Stewardship Initiative
Numerous solutions to the aluminum problems have been proposed, but they come with problems of their own. For example, one such solution is to substitute steel, but this more expensive, much heavier, and harder to recycle. By using steel, renewable energy installations will be less financially viable, harder to transport, less effective, among many other reasons.
One organization, though, has an interesting idea. The Aluminum Stewardship Initiative is a non-profit that seeks to set the standards for cleaner aluminum production and to certify the companies meeting them. Their mission is to “recognize and collaboratively foster responsible production, sourcing, and stewardship of aluminum.” Their priorities through 2030 are
- to push the industry towards mitigating climate change by keeping global temperature rise under 1.5 degrees Celsius
- to drive circularity by reducing metal losses and creating better designs for waste and pollution
- to drive nature-positive actions by repairing and maintaining biodiversity
- and to drive respect for human rights through local action, better supply chains, and empowerment.
Through academic, government, and industry engagement, the Aluminum Stewardship Initiative hopes to positively influence policy, create valuable plans of action, facilitate the development of better methods and technology, spread key information to those that need it, create meaningful partnerships, and to drive change for a more efficient and environmentally friendly aluminum industry. So the initiative seems to be growing rapidly, as they already have hundreds of members, including major aluminum producers like Alcoa, ALBRAS, Chinalco, Hongquio, Emirates Global Aluminum, just to name a few.
While this is certainly a major step in the right direction, it’s uncertain if it will be enough to reverse climate change and usher in a cleaner, sustainable world.
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