Long Duration Storage Systems Can Solve Lithium-Ion's Shortcomings

As grid operators increasingly add renewables to their energy mix, they are faced with finding solutions for intermittency. Until now, the energy storage market has mainly revolved around the production and consumption of lithium-ion (Li-ion) batteries. However, Li-ion batteries are not a catchall for energy storage. They are plagued by a variety of shortcomings, for which long duration energy storage systems provide solutions.

The Limitations of Li-ion

Firstly, Li-ion batteries have a relatively short duration of between 2 to 4 hours. Many renewable plants are set up to shift peak loads and reduce the need for peaker plants. However, peak consumption hours often last longer than 2 to 4 hours, and in an increasingly electricity-reliant world, peak hours will only become more drawn out. For example, compressed air energy storage systems are promising where geography permits, despite location being a limiting factor. One of the only large-scale plants built, the McIntosh Alabama plant, has a storage duration of 26 hours.

Secondly, Li-on batteries have a relatively short lifespan. They often only last 2-3 years, not making it an optimal solution for companies that are trying to be more eco-friendly. Flow batteries provide a good counterbalance to this problem. They have a lifespan of around 25 years and are a low maintenance technology. In recent years, the price of flow batteries has decreased sharply, making them one of the primary potential competitors to Li-ion batteries.

Thirdly, Li-ion batteries can pose significant fire hazards. Fire outbreaks such as the Victorian Big Battery project in Australia earlier in 2021, which couldn’t be extinguished for 3 days, are a considerable detractor. Vanadium flow batteries (VFBs) are a much touted response to this pitfall. Thanks to the aqueous electrolytes (in lay terms, the battery is full of water) used in the batteries, they are non-flammable by nature.

Lastly, Li-ion batteries traditionally pose a moral qualm. Cobalt is a rare element often used to make the batteries, and its acquisition has a high human cost. As uncovered by The Washington Post in 2016, 60% of the cobalt used worldwide in phones, laptops, and many other applications of which Li-ion batteries are but one, comes from mines in the Democratic Republic of Congo. In these mines, safety hazards, child labor, and inhumane working conditions are the norm. Furthermore, the provenance of cobalt is obfuscated by murky supply chains, meaning that even well-meaning companies often are unable to assure that the mines’ workers do not labor in abusive conditions. One way of avoiding these moral issues is not to use cobalt, which is a possibility in water-based VFBs.

The Future of Long Duration Storage Might Involve a Greater Mix of Battery Technologies

Li-ion batteries will continue to be a key player in the energy storage market but their drawbacks are attracting more investment in other technologies. Though many of the long duration storage systems are not yet viable on a large scale as Li-on batteries are, increased interest in them will drive investment from both the private and public sector. The industry can expect to see an increase of Li-ion plus long duration hybrid projects as well as an increase of purely Li-ion and purely long duration storage projects for the foreseeable future. To read more about long duration storage technologies, read Guidehouse Insights’ report, Market Data: Utility-Scale Long Duration Energy Storage.