“For Enel Green Power, renewable plants integrated with lithium batteries are now part of our commercial offering.”
EGP is a global leader in the use of energy storage systems. This position of leadership has been achieved through intense innovation we’ve performed for several years, constantly improving our skills in the technologies available and figuring out the best ways to use them to respond to the needs of our clients and of the electrical grid.
Today’s storage: lithium batteries
The storage systems emerging with increasing strength are based on lithium batteries, a varied set of technologies united by their use of lithium ions to store energy.
Technology based on Nickel, Manganese and Cobalt (NMC), the most suitable for use in electric vehicles, has gone through a real revolution in recent years. The increase in global demand for e-cars has led the main producers to increase the production of batteries, leading to so-called giga-factories, especially common in Asia, which are able to produce dozens of GWh in batteries each year. Increased production has naturally had an impact on pricing, down by almost 80% from 2010 to 2016, according to Bloomberg data.
The resulting virtuous process has fostered, together with evolving regulations in many markets, the spread of batteries as an effective tool to boost the integration of renewable energy into electrical grids, as they can replace fossil fuel systems in many grid regulation services.
EGP’s Sustainable Batteries
For Enel, non there is no innovation without sustainability. We are already dealing with the entire life cycle of batteries, from their starting materials to the end of their service life.
As concerns raw materials, lithium batteries use some materials that are difficult to retrieve, and some of the more common chemicals, like the NMC mentioned above, use cobalt, extracted in politically unstable areas of the world, where the exploitation of child labour is tragically the norm.
This is why producers and operators are trying to reduce the cobalt content in their batteries with new solutions that can maintain the same performance in terms of storage capacity and duration.
Furthermore, as a member of the Global Battery Alliance, sponsored by the World Economic Forum, EGP is trying to identify, together with materials providers, battery builders and users and international associations, ways to trace raw materials starting from their extraction, guaranteeing a sort of certificate of origin to products coming onto the market.
Then there is the issue of managing batteries at the end of their service life. According to data from the Global Battery Alliance, by 2030, 11 million tonnes of lithium ion batteries will be at the end of their service life, and most of these will come from the mobility sector. This is why EGP is studying, together with other business lines at Enel, the possibility of using batteries originally used in electric vehicles for integration into renewable plants and to provide services to the electrical grid, creating a virtuous process of the circular economy.
“As a leading company in sustainability, we are defining sustainability indicators for the choice of storage systems to integrate into our plants. Therefore, suppliers are encouraged to adopt a ‘design-to-recycle’ approach for their products, with economic and environmental advantages.”
For storage systems that have completely exhausted their life, we must plan for effective recycling and recovery processes, carried out with maximum transparency. For this reason, at EGP, we are defining sustainability indicators for the choice of storage systems to integrate into our plants. In this way, suppliers are urged to adopt a “design-to-recycle” approach for their products, in order to guarantee maximum attention to the environment and to the resources it provides. These approaches can be winning solutions for the cost reduction of storage systems.
Beyond lithium batteries
For Enel Green Power, looking to tomorrow means sustainability and innovation. On this second point, the future of batteries is full of technologies aiming to join lithium in guaranteeing the flexibility necessary for an electrical system 100% based on renewable sources.
Flow batteries, for example, are now a step away from large-scale commercialisation. IOn the coming years, they will have an important place next to their lithium “cousins”.
Due to the specific technology of flow batteries, the energy stored and the power supplied are not intrinsically linked, a characteristic that makes them especially suitable for storage systems connected to renewables, since there is a necessity to use the sun’s energy, for example, for our evening and night-time consumption.
Furthermore, flow batteries are built with raw materials that are much less problematic as regards availability and have a limited environmental impact compared to their lithium cousins, for improved sustainability.
However, they are still fairly costly, especially for industrial-sized applications.
Alongside flow batteries, promising mechanical energy storage solutions are appearing, such as Compressed Air Energy Storage (CAES) and Air Energy Storage (LAES). They are similar technologies, which use compressed air or compressed air cooled to liquefaction, to store energy.
The potential advantages of this type of technology lie in the use of consolidated technologies whose cost decreases notably by increasing the size of plants and in the lack of significant degradation in storage capacity over the lifetime of the plant. On the other hand, the spread of CAES systems, already proven on an industrial scale, has so far been limited by the need to have natural reservoirs available, like underground cavities, which are not so widespread and easily usable as one might like. LAES could overcome this limitation and be competitive with other technologies.
The future that awaits us
The push toward a 100% renewable world, with resulting massive investments in the field of energy storage, is opening up enormous space for the development of new technologies. Every day, there are reports of market solutions to increase the capacity of storage systems, increase their efficiency, lengthen their service life and drastically reduce costs.
As regards lithium batteries, research is pushing towards the use of silicon anodes or solid-state electrolytes, which would be able to significantly increase the energy density of the systems built.
Then there are batteries with new chemicals, not based on lithium, or even with purely mechanical systems, which use gravity to store energy, lifting weights to high levels when it needs to absorb energy and generating new energy when the weights move down.
And hydrogen? It has been used for small systems for years, especially in remote areas, but it still hasn’t taken hold for mobility or in stationary applications because of low conversion efficiency and consistently high costs. However, hydrogen generated from renewable sources could be the winning answer to lowering carbon dioxide emissions in the transport and industrial sectors. Cars, or even better, heavy vehicles, would benefit from the large quantity of energy contained in hydrogen to go long distances, while chemical industries could do without the hydrogen produced from methane, to move to green hydrogen generated with electrolysis from renewable sources.
Science fiction? Perhaps at the moment, but even though some of these technologies are still taking their first steps, for EGP and for the entire electricity sector, storage systems are now a reality and an indispensable element for a world that is 100% powered from renewable sources.