The energy sustainability potential of cities

To make the energy transition a reality, some experts estimate that between 2015 and 2050, the global electric passenger vehicle (EV) fleet must increase from 1.2 million to 965 million, battery electricity storage capacity from 0.5 gigawatt-hour (GWh) to 12,380 GWh, and installed solar photovoltaic capacity from 223 GW to over 7,100 GW. Which implies that the amount of materials and metals demanded by a decarbonised economy will be immense. 

One assessment recently concluded that the expected demand for 14 metals -including copper, cobalt, nickel, and lithium, essential for the production of renewable energy, EVs, fuel cells, and electricity storage technologies- will grow substantially in the coming decades. Thus, an increase of 87,000% in the demand for materials for EV batteries, 1,000% for wind generation, and 3,000% for solar photovoltaic is envisaged for the period 2015-2060. The World Bank clearly summarises the situation: "the transition towards clean energy will be significantly mineral-intensive".

Many of the necessary minerals and metals for low-carbon technologies are considered "critical raw materials" or "technologically critical elements", terms that underline the fact that not only are they strategic and of great economic importance, but also present a high risk of supply shortages and price volatility, with major geopolitical implications. Furthermore, the mining of these metals is in itself energy-intensive and may involve significant environmental impacts and serious social consequences, so the paradox is that the energy transition and the associated digital revolution will not be as green as is often assumed.

In order to ensure the future supply of these raw materials, it will undoubtedly be essential to drive efficiency (greater production and use of the final product per unit of primary resource used) and recycling. However, even so, it will also be necessary to increase the pace of primary resource extraction, sustainably diversifying supply chains, exploiting new mines, and developing new flows of resources, such as obtaining metals from seawater and geothermal brines, as well as replacing, recovering, and reducing the intensity of the use of materials. And, in any case, we must be aware that, although in the short term land-based mining will continue to be essential to satisfy the growing demand for clean and digital technologies, longer term we will have to consider the exploitation of deep-sea mineral sources very seriously. Who said it was easy?

When an electric vehicle (EV) battery reaches the end of its useful life, it loses any "green" qualities it once had. If it ends up in a landfill, its cells can release toxic substances. And recycling it is more difficult than you would think. In this context, scientists have offered to seek a solution to this emerging question: How can we recycle the millions of EV batteries that the automobile industry is expected to produce in the coming decades? The heart of the matter is that today's batteries are not designed to be recycled. This wasn't such a big problem when EVs were rather rare, but by 2030 around 145 million EVs may be on the road, compared with 11 million last year. 

At the same time, governments are considering making recycling mandatory. The EU is expected to adopt its first requirements this year, whereas in the US, although the federal government hasn't announced it, several states are exploring their own options for a similar requirement. Nevertheless, complying with these regulations will not be easy. Batteries are significantly different in their chemistry and construction, making it difficult to create efficient recycling systems. And often, their cells are joined with resistant glues that make them difficult to break down, which creates an additional economic hindrance: sometimes, it is cheaper for manufacturers to purchase recently mined metals than to use recycled materials. Improving the ability to recycle prevents pollution and helps governments ensure the availability of important metals whose supply is controlled by very few countries. On the one hand, disposing of EV batteries is a waste management concern, but on the other hand, it's a great opportunity to generate a secondary source of critical sustainable materials. 

To encourage recycling, governments and industry are investing in diverse research initiatives. For example, the US Department of Energy supports the ReCell Center, the United Kingdom backs the ReLIB project, and China is behind the development of a recyclable battery (Blade Battery) that was developed last year by BYD. These advances, driven by a 2018 regulation that summoned EV manufacturers to ensure that battery components be reusable, resulted in China recycling more lithium batteries today than the rest of the world. 

Obviously, governments must play a decisive role in facilitating and promoting recycling. Along this line, in China's footsteps, they should maybe begin by defining the responsibilities of EV manufacturers and sellers and those of users who purchase and use them.