Tackling climate change is one of humanity’s main challenges from both urgency and consequences perspectives. In 2015, 196 countries committed in Paris to limit global warming below 2 ℃, preferably around 1.5 ℃.

In parallel, the circular economy has also recently evolved. The circular economy has been defined as “an economic system of closed loops in which raw materials, components and products keep their quality and value for the longest possible and systems are fueled by renewable energy sources.”

The circular economy aims to decouple economic development from the linear dynamics of finite resource extraction, use, and disposal (Velasco-Muñoz et al, 2021). But can the circular economy help to tackle climate change?

According to the Circularity Gap Report, “The world can maximize chances of avoiding dangerous climate change by moving to a circular economy, thereby allowing societies to meet the goals of the Paris Agreement on Climate Action.” Many countries have acknowledged the role of the circular economy in achieving net zero.

The World Resources Institute notes that one-third of nationally determined contributions – climate action plans by each country to cut emissions and adapt to climate impacts – include mention of a circular economy. A study by Platform for Accelerating Circular Economy (PACE), WRI, Chatham House and the National Renewable Energy Laboratory (NREL) highlights that circular economy strategies can: i) complement decarbonization measures to reduce greenhouse gas emissions; ii) enhance adaptation to a changing climate; and iii) support the sustainable scaling of the clean energy transition.

Let’s focus on the clean energy transition. The implementation of energy efficiency measures and deployment of renewable energy technologies could lead to over 90% reduction in energy-related GHG emissions by 2050.

However, these actions would only address about 55% of global GHG emissions reduction needs because the remaining 45% of global GHG emissions are related to production of goods and land management.

Renewable energy technologies and supporting infrastructures are resource intensive as large amounts of critical raw materials, composites, plastics, metals, and concrete are required in the construction of renewable energy production plants.

Therefore, renewable energy technologies must be manufactured and managed in the most environmental, economic, and socially sustainable way. To this end, circular economy strategies can narrow, slow, and close resource loops in helping to achieve these goals (Bocken et al. 2016). However, technology design for the circular economy is challenging and demands a better understanding of resource requirements, material alternatives, use performance and end-of-life solutions to identify the most suitable life cycle management strategies. 

Solar and waste management

For solar, full life cycle assessment studies have demonstrated that most of the impacts are associated with the production and the end-of-life stages (Mukoro et al.,2021). Solar-production countries with predominantly fossil-based energy mix will generate devices with higher embedded greenhouse gasses (Gaete-Morales et al., 2019). Mainland China, with a 64% coal-based electricity mix, accounts for 66% of the global production of solar photovoltaics.

Waste treatment system is key. In the Global North, extended producer responsibility policies  make the manufacturers of solar systems pay for their treatment. However, in lower-income countries, the waste treatment systems are much more precarious and the burning or just dumping of the solar power systems can lead to the leaching of toxic heavy metals like cadmium and lead, and the loss of scarce materials like silver (Kinally et al., 2022).

Poor maintenance, cheaper and faulty devices, and batteries reduces solar systems life in developing countries. This situation increases the environmental impacts per kWh produced. Circular economy principles can help to improve these situations and reduce the impacts.

Production impact can be reduced by narrowing the use of both energy and materials. The life expectancy can be increased by designing robust products that can be repaired, refurbished and remanufactured. The development of efficient recycling systems can close cycles to reduce human toxicity impacts and increase materials recovery.

Wind and critical minerals

Another sustainability issue arises in the wind turbines (WT) that can house around 25,000 components with more than 2,000 tonnes of material, of which critical raw materials and composites are a challenge for the wind industry (Mendoza et al. 2022).

Critical materials are affected by supply chain disruptions and geo-political risks, and the increase in the demand of critical materials by 2050 could lead to 96 Mt of CO2 emissions—equivalent annual GHG emissions by Austria, Greece or Romania (based on Marx et al. 2018).

Recycling, recovery and secondary supply of these critical materials could mitigate accessibility risks and constraints. However, current recycling levels are limited due to reduced efficiencies and resource requirements.

Other circular economy strategies should be explored, including:

• Material substitution. For example, the replacement of Dysprosium and Neodymium by Cobalt and Terbium.
• Permanent magnets substitution. For example, neodymium-based magnets could be replaced with iron-nitride magnets.
• Generators substitution. For example, the replacement of permanent magnet direct drive generators by doubly-fed induction generators, electrically excited synchronous generators or high temperature superconducting generators.
• Material efficiency improvements. For example, improving the efficiency of production processes.
• Reuse. For example, facilitating the direct reuse of permanent magnets that are in good condition.
• Recycling. For example, improving the design of the permanent magnets to facilitate disassembly into components and material recovery.

Composites in manufacture are also an issue making recycling to be technically complex and expensive. Although there are several recycling alternatives available, including mechanical grinding, pyrolysis, high voltage pulse fragmentation, solvolysis and fluidized bed, they have technical and economic challenges to overcome—low process efficiency, material contamination, and reduced quality of the process outcomes.

Consequently, ensuring optimal WT design and life cycle management by applying eco-design and circular economy life cycle thinking (Mendoza et al. 2017) is crucial for a sustainable energy transition.

Conclusions and next steps

The deployment of renewable energy technologies is of utmost importance to achieve the climate-neutral goals. However, this deployment should be accompanied by resource efficiency improvements driven by the implementation of circular economy strategies.

Nevertheless, not a single one-size-fits-all circular economy solution is applicable to the renewable energy sector. A system-level perspective must be applied to identify which combination of circular economy strategies and solutions is the most suitable for the short-, medium- and long-term. This approach should be supported by the provision of incentives and the development of eco-design and end-of-life management policies applicable to renewable energy technologies.

In this process, active collaboration between researchers, industrial manufacturers, renewable power plant managers and government bodies is crucial. We look forward to working with these various stakeholders to achieve these goals.

References

Bocken, N.M.P., de Pauw, I., Bakker, C., van der Grinten, B., 2016. Product design and business model strategies for a circular economy. Journal of Industrial Production and Engineering 33(5): 308-320.

Gaete-Morales, C., Gallego-Schmid, A., Stamford, L., Azapagic, A., 2019. Life cycle environmental impacts of electricity from fossil fuels in Chile over a ten-year period. J. Clean. Prod. 232, 1499–1512.

Velasco-Muñoz, J.F., J. M. F. Mendoza, J. A. Aznar-Sánchez, A. Gallego-Schmid, 2021.Circular economy implementation in the agricultural sector: Definition, strategies and indicators. Resources, Conservation and Recycling, Volume 170, 105618.

Kinally, C., Antoñanzas-Torres, F., Podd, F., & Gallego-Schmid, A., 2022. Off-grid solar waste in sub-Saharan Africa: Market dynamics, barriers to sustainability, and circular economy solutions. Energy for Sustainable Development, 70, 415-429.

Marx, J., Schreiber, A., Zapp, P., Walachowicz, F., 2018. Comparative Life Cycle Assessment of NdFeB Permanent Magnet Production from Different Rare Earth Deposits. ACS Sustainable Chemistry and Engineering 6(5): 5858–5867.

Mendoza, J.M.F., Sharmina, M., Gallego-Schmid, A., Heyes, G., Azapagic, A., 2017. Integrating backcasting and eco-design for the circular economy: the BECE framework Journal of Industrial Ecology 21(3): 526-544.

Mendoza, J.M.F., Gallego-Schmid, A., Velenturf, A.P.M.,  Jensen, P.D., Ibarra, D., 2022. Circular economy business models and technology management strategies in the wind industry: sustainability potential, industrial challenges and opportunities. Renewable and Sustainable Energy Reviews 163: 112523.

Mukoro, V., Gallego-Schmid, A., Sharmina, M., 2021. Life cycle assessment of renewable energy in Africa. Sustainable Production and Consumption, 28, 1314–1332.

This blog is one in a series produced by Future Earth’s Systems of Sustainable Consumption and Production (SSCP) Knowledge Action Network.