Why energy storage and recycling go hand in hand

Critics of renewable energy like to point out its potential defects: how do you provide heating, lighting and other services when the sun doesn’t shine and the wind doesn’t blow? The answer lies in three key factors:

- Increased complementarity of multiple renewable energy sources and generating plants.

- Increasing digital interconnectivity at low volatage (LV) and medium voltage (MV) grid levels.

- The implementation of effective Energy Storage Systems (ESS).

When it comes to ESS, one such system, the Battery Energy Storage System (BESS), is becoming a vital enabler of the energy transition.

At the same time, critics also argue that electric mobility, critical in the transition to net-zero, sounds wonderful in theory but what do you do with all the batteries once the vehicles have completed their life cycle? Disposal poses a threat to the environment, much like the fossil fuels that electric cars and renewable energy are meant to replace.

However, there is good news too: used electric car batteries can be recycled at renewable energy plants. Not only that, but they can also contribute to solving the question of energy storage. It’s a case of killing two birds with one stone and aligns with the circular economy principles that aid energy transition.

Companies are developing exciting projects throughout the world. The Japanese car manufacturer Nissan has been particularly active in this respect with its Nissan LEAF vehicle, which first came onto the market in 2010. At the Enel Group, we have had the chance to work with Nissan on the “Second Life” project in Melilla, a Spanish city on the North African coast not electrically interconnected to the Spanish mainland. It, therefore, has its own electricity grid and a local thermal power plant supplies the energy.

The “Second Life” project has been integrated and powered by Loccioni, an Italian system integrator specializing in sustainable storage systems. It takes disused Nissan LEAF batteries and uses them for a storage system with an overall capacity of 4MW and maximum energy storage of 1.7MWh. The system uses 78 Nissan Leaf batteries, 48 of which have been recycled and 30 of which are brand new. It can inject power into the city’s grid for up to 15 minutes, should the power plant become unavailable. This project perfectly shows the great potential that exists for disused car batteries.

A similar project is under development in Italy at Fiumicino “Leonardo Da Vinci” international airport, the country’s largest airport. The plan developed by Enel X with Aeroporti di Roma, the company managing Rome Airports, is to build a 30MW solar park, which should be ready by 2024. It will feature a 10MWh storage system that uses recycled electric vehicle batteries. They will store the excess energy produced by the plant during the day to cover evening demand peaks at the airport.

When disused car batteries end their life, they can be recycled for other purposes. In this respect, Endesa is developing mainland Spain’s first electric battery recycling plant with Urbaser, a waste management and recycling company. The plant, which should come into operation at the end of 2023, will be located at Cubillos del Sil in the province of León in the northern part of the country. It will be developed on the site of a thermal power plant that is currently being dismantled and is part of a project for repurposing disused power plants.

Nor are electric car batteries the only components from renewable energy products that can be adapted for energy storage once they reach their life cycle. The blades at wind farms, for example, can also be used for energy storage systems. Wind farms are particularly challenging, as the towers and blades in turbines are often made from carbon-intensive materials like steel and concrete, even though one company, Modvion, is now making towers from laminated veneer lumber in Sweden. But what happens to the more “traditional” steel and concrete towers at the end of their (ordinarily 30-year) life cycle?

These components can be recycled for many purposes (such as building material, sanitary and furnishing products, and tubing), but they can also be reused for energy storage. A Swiss company, Energy Vault, is developing a unique system for gravitational storage. The system, which is inspired by hydroelectric power plants, uses huge blocks of material which are raised when excess energy is produced and lowered when it is required: electricity is generated by the force of gravity. The blocks are stabilized by recycled material from blades.

These are just some of the original techniques for energy storage that are being developed around the world. Battery storage is in many ways the key to the energy transition and all of the systems described use recycled materials. They are excellent examples, not only of the circular economy approach but of energy that is sustainable in every sense.