Unearthing the Mining and Recycling Challenges of Renewable Energy

Renewable energy technologies – like solar panels, wind turbines, and batteries – are expected to grow exponentially in the next few decades. Over a quarter of the world’s energy is now met by renewable sources, an increase driven by favorable economics, regulation, and efforts to move away from climate-change-causing fossil fuels. However, renewable energy technologies require more critical minerals than their fossil fuel predecessors, leading to significant additional critical mineral demand and concern that mineral supply shortages could lead to a slower, or more expensive, energy transition.

Research, led by Tessa Lee, MESc at Yale School of the Environment and an Environmental Research & Education Foundation (EREF) scholar, has quantified the mineral requirements of the renewable energy transition in the U.S. for wind turbines and solar panels. Tessa’s work calculates the raw material requirements of multiple decarbonization pathways, as well as ways mineral demand could be reduced, such as recycling.

The U.S. government designates minerals as ‘critical’ based on the likelihood of supply shortages and the impact of those shortages on the economy. Many of the key minerals required to produce wind turbines, solar panels, electric vehicles, and batteries are critical. Global studies, such as those by the World Bank and International Energy Agency, find that there are enough critical minerals available on earth to build the necessary renewable energy technologies for a global energy transition. The issues arise when geopolitics, negative impacts of mining, and long lead times (around 15 years) for new mines are considered. The question is, how can the U.S. secure the critical minerals it needs, considering it has little domestic production, and is competing for global minerals with other countries, many of whom are also increasing their demand?

Tessa’s research finds that meeting the U.S. goals set forth in the 2015 Paris Climate Agreement (to keep global warming below 2 degrees) could increase the annual demand for critical minerals five-to-seven times compared to the present energy system. For some minerals, such as the rare earth elements (REE) used in wind turbines, the yearly requirements could be as a high as 33 times higher, which would require up to 49% of current global REE supply, far beyond the U.S.’s proportional share. For Tellurium, which is used in 40% of U.S. solar panels, full decarbonization could exceed current global supply, meaning either that tellurium production would need to rapidly increase, or the U.S. would have to limit its use of tellurium-containing panels (which are manufactured by the largest U.S. solar panel manufacturer).

Shortfalls in domestic critical mineral supply will likely increase the U.S.’s import reliance on countries like China and the Democratic Republic of Congo, which currently produce significant proportions of the world’s energy-critical minerals. In addition, rapid increases in mineral demand are also likely to increase the cost of raw materials, thereby raising the price of the energy transition.

One solution to the shortage and expense of critical minerals will be recycling existing technologies. Many of the minerals in wind turbines and solar panels can be partially extracted at end-of-life and repurposed into new equipment. Currently, however, there’s simply not enough equipment reaching that end-of-life phase to significantly offset shortages in material supply. The impact is particularly small in the next few decades as the scale of new wind turbines and solar panels being built vastly outpaces the number retiring at the end of their useable life.

The importance of equipment recycling will continue to grow as the number of waste turbines and solar panels increase. Toward the second half of the 21^st century, research suggests the energy system will reach a near steady state where the number of renewable energy technologies being built will equal those produced as waste. At this point, a successful closed loop recycling system could fulfill a significant proportion of mineral demand, reducing the need for continued intensive mining of critical minerals.

For the average consumer, three questions emerge:

There is no doubt mining will need to increase to manufacture the wind turbines and solar panels required for the transition from fossil fuels. The questions we now need to start asking are how we can scale up mining sustainably, to minimize damage to the earth’s environment and its inhabitants? Further, how can we manage the potential geopolitical risks of transitioning from a fossil fuel dependent to a critical mineral dependent energy sector? These are tough questions with no easy answers, but if the U.S.’s target of reaching a carbon pollution free electricity sector by 2035 is to be met, they will need to be answered, and soon.