As countries increasingly demand long-duration energy storage solutions for their new power systems, more lithium battery enterprises are targeting this niche market.
The 4-hour storage duration is typically regarded as the "lower limit" for long-duration energy storage technology, and currently, 4-hour lithium battery storage systems are being adopted in China, the United States, and several other regions.
Just last week, over 5 GWh of 4-hour storage projects were tendered domestically, primarily using lithium battery storage and concentrated in Qinghai and Xinjiang—two major renewable energy provinces in northwest China. These projects include the State Power Investment Corporation's Huanghe Hydropower 350MW/1.4GWh storage system in Qinghai, a 300MW/1.2GWh molten salt and electrochemical storage project in Changji, Xinjiang, a 0.8GW/3.2GWh storage equipment procurement for the Tianshan North Slope Renewable Energy Base project, Xinjiang Huadian's 1GW/4GWh grid-following storage system procurement, and Dongfang Electric's 500MW/2000MWh wind power EPC project with storage in Qinghai.
The U.S. is the world's largest market for long-duration energy storage, with an average storage duration of 3.3 hours. Chinese lithium battery enterprises have already achieved 4-hour storage system deliveries in this market.
According to independent power producer (IPP) Hecate Energy, the company plans to deploy a 310MW/1240MWh Ward Hill battery energy storage system, using CATL's EnerX containerized battery system with a 4-hour duration and a single unit capacity of 5.64MWh.
Other markets, such as Malaysia, are also adopting long-duration energy storage solutions. The 100MW/400MWh battery storage system project in Sabah will use Sungrow's battery storage system, with construction starting in September 2024 and completion expected by June 30, 2025.
In the past, lithium battery storage was typically considered suitable only for 2-4 hour durations. However, technological advancements have changed this perception, with lithium battery storage now capable of supporting 4-12 hour durations, positioning itself as a competitor to another recognized long-duration technology—flow batteries.
UK-based battery storage developer and operator Statera Energy is planning a 400MW/2400MWh Chickerell battery storage system, which received approval from the UK Parliament in August. According to parliamentary documents, this 6-hour duration project will use BYD's MS Cube ESS container products.
In October, Canadian IPP Capstone Infrastructure and Denmark's Eurowind Energy proposed deploying a 400MW/3200MWh standalone battery storage system in California. Their joint venture, Levy Alameda, will develop and implement the Potentia-Viridi system, an 8-hour duration project planned to use modular lithium iron phosphate (LFP) batteries. The deployment is set to begin in early 2026, with operations starting in Q2 2028.
In addition to BYD, companies such as Hithium, EVE Energy, and REPT are also actively pursuing long-duration energy storage.
Hithium is accelerating its efforts in this field. In December 2023, the company launched the MIC 1130Ah ultra-large capacity battery designed for the 4-8 hour storage market. In September 2024, Hithium introduced a 6.25MWh storage system solution tailored for 4-hour applications. On October 15, 2024, during the Solar & Energy Storage Expo in Saudi Arabia, Hithium presented a desert-specific storage system capable of over 12 hours of continuous discharge. On October 29, 2024, Hithium spearheaded the construction of the world's first integrated long-duration storage zero-carbon industrial park in Heze, with a planned investment of 13 billion yuan.
EVE Energy plans to commence production of its 628Ah storage plant's first phase in December, marking the industry's first mass-produced large-Ah storage product, meeting the market's long-duration storage needs.
REPT's specially developed 564Ah cell for 4-hour plus applications boasts over 10,000 cycles and a 25-30 year calendar life. Based on this cell, REPT has created the 20-foot Powtrix storage system, which meets the growing global demand for 4-hour plus long-duration storage, with a DC-side installed capacity exceeding 6MWh, an efficiency of over 95%, and a system lifespan of more than 25 years.
