The technology defining energy storage
Advances in battery technology will soon have the potential to resolve one of the most persistent dilemmas for the energy sector – that of energy storage. For renewables in particular, one of the key criticisms is its variability, with storage technologies representing an opportunity to address supply challenges.
Across the world, the industry has focused on solving the storage challenge, increasing capacity while reducing the cost of storing energy. In fact, electricity storage has played a crucial role in enabling the energy transition globally, boosting renewable energy generation and enabling rapid decarbonisation.
In solving one of the industry’s main challenges, various technologies have emerged, with Li-ion batteries emerging as the dominant solution for stationary energy storage for electric utilities.
About Li-ion batteries
A lithium-ion battery or Li-ion battery is a type of rechargeable battery mostly used in consumer goods. Li-ion batteries are also quickly becoming an attractive candidate for large-scale, stationary applications, as well as for sustainable automotive and back-up power supply applications. Over the past years, Li-ion batteries have emerged as the most widely deployed technology for stationary energy storage projects. 
Today, Li-ion batteries have been installed in stationary energy-storage applications ranging from systems handling just a few kilowatt-hours, such as residences with rooftop photovoltaic arrays, to multi-megawatt back-up energy storage for national grids.
The cost reduction potential of Li-ion batteries for stationary applications is is significant. Li-ion battery cost could fall by more than 50-60% by 2030. 1
Global manufacturing capacity for Li-ion batteries is currently around 131 GWh per year, but this is set to leap to over 400 GWh by 2021 to meet the increasing demand caused by burgeoning population growth.
While Li-ion batteries currently represent a compelling case in terms of cycling, cost and flexibility, new technologies are emerging and proving their competitive worth for stationary storage applications.
Recently, researchers at MIT have developed an innovative molten-electrode battery that could be used for grid-scale applications. The new approach, which moves away from the sodium-nickel chloride batteries, could lead to inexpensive batteries large enough to make intermittent renewable power sources practical for grid-scale storage.
Through its research lab X, technology giant Alphabet is developing a system for storing renewable energy that has the potential to last longer than Li-ion batteries and compete on price with other existing clean energy storage methods. Malta aims to capture clean energy when it’s being produced by using salt to store it on a large scale with the aim of closing the gap of when renewable energy is available and when it’s needed. With this move, X is stepping into a market that could see about $40 billion in investment by 2024.
Deploying large-scale storage
While competing technologies are being quickly developed, Li-Ion remains the de-facto choice for stationary storage applications in the industry. Countries such as Australia have deployed large-scale lithium batteries to generate dispatchable renewable energy, and researchers around the world will continue to innovate to find solutions to improve battery performance and reduce costs.
 Assessment of Strategy and Execution for 13 Non-Li-Ion Battery Energy Storage Vendors. Navigant Research. Available at : https://www.navigantresearch.com/research/navigant-research-leaderboard-non-lithium-ion-batteries-for-grid-storage . Last accessed July 2018.
 New Energy Storage Battery Technology Answers the Need for Li-Ion Replacement. Available at: http://www.powerelectronics.com/alternative-energy/new-energy-storage-battery-technology-answers-need-li-ion-replacement Last accessed July 2018.