# Tesla in the United States unveiled Megablock, a large battery energy storage system (BESS), on Sept. 8 (local time). Set to roll out starting next year, Megablock is built by consolidation of multiple 20-foot container-sized batteries (Megapack 3) that supply 5 MWh (megawatt-hours) of power. The company said it can secure up to 1 GWh (gigawatt-hours) of storage capacity in about 20 days. Mike Snyder, vice president for Tesla Energy and charging institutional sector, said, "It won't take even a month to supply power to 400,000 households."
# China's BYD also unveiled on the 21st of the same month "Haohan," a next-generation large BESS to compete with Megablock. Haohan can supply 15 MWh of power. Earlier in Feb., the company signed a supply contract with Saudi Electricity Company (SEC) for an energy storage facility with a capacity of 12.5 GWh. Adding a previously conducted 2.6 GWh project brings the total to 15.1 GWh, the largest among energy storage facilities built to date.
The battery industry, which had slowed briefly due to the electric-vehicle chasm (a temporary demand plateau before an innovative product goes mainstream), is finding new growth opportunities in energy storage systems (ESS). The world's grid battery storage capacity (cumulative) surged from 12 GWh in 2020–2024 to 176 GWh, recording a 95% compound annual growth rate (CAGR). According to BloombergNEF, the world's new BESS installations this year are expected to reach 92 GWh, up 23% from 2024, marking a record high for the second straight year. Korea's three battery makers that had staked their fortunes on EV batteries—LG Energy Solution, SK On, and Samsung SDI—expect ESS batteries to become a new opportunity as risks grow from the EV chasm and China's overtaking. A prime example is LG Energy Solution's deal in July to supply Tesla with 20 GWh of ESS annually. Tesla, which makes EVs, is also the No. 1 private power generation package provider, bundling solar power systems and ESS in a single sale. Economy Chosun analyzed, through expert interviews, the backdrop and outlook for the BESS market's high growth driving the energy storage revolution.
Energy storage revolution even Trump couldn't stop
"We expect cumulative global BESS installations to reach 2 TW (terawatts) by 2035, eight times the level in 2025." The forecast by Ishu Kikuma, a BloombergNEF analyst, shows that the heyday of BESS—dubbed "giga storage" and "mega batteries"—is coming. Although the U.S. Donald Trump administration is putting the brakes on the expansion of renewables such as EVs and solar power, the energy storage revolution is expected to accelerate. The drivers include the plunge in battery prices caused by the EV chasm and battery overproduction from China, the rapid rise in penetration of variable renewables such as solar and wind, surging power demand from artificial intelligence (AI) data centers, and innovation in new energy storage technologies.
Lithium-ion battery pack prices fell from $806 per kWh (kilowatt-hour) in 2013 to $115 in 2024. Prices for grid-connected batteries are approaching the historic low of EV battery prices. As the share of solar and wind power—where natural variation dictates output—rises, demand for BESS is growing in tandem. Sophia Leandra Wintz, a consultant at Adelphi, a German environmental consulting firm, said, "BESS is the most appropriate device to operate power systems flexibly, stably, and with resilience as the share of solar and wind power increases." In fact, according to the International Renewable Energy Agency (IRENA), renewables accounted for 67% of the electricity stored by ESS worldwide. BESS is also emerging as a solution to the mismatch between generation and transmission capacity due to delays in grid expansion. According to the World Energy Outlook 2025, released by the International Energy Agency (IEA) in Nov., grid investment has plateaued at about $400 billion a year, while generation investment centered on solar has reached $1 trillion.
The race by big tech to build AI data centers is also contributing to the expansion of the BESS market. AI data centers that use a large number of graphics processing units (GPUs) consume two to three times more electricity than regular data centers. Due to the increase in AI data centers in 2025, an additional 8%–12% (15–20 GW) of power was required in North America alone, and 10%–15% (25–30 GW) in the Asia-Pacific region. Microsoft (MS) is using BESS at its data center in Sweden. Meta also built solar power and BESS together at its data center in Arizona.
Large battery products that have achieved technological innovation, such as Tesla's Megablock and BYD's Haohan, are greatly improving installation speed and efficiency. Accelerated development of sodium-ion batteries, which are emerging as an alternative to lithium-based batteries because they are inexpensive and have a lower risk of fire, also supports BESS growth.
China and the United States, 70% of the global market
China and the United States account for 70% of the global BESS market. China is the world's largest battery producer, making three out of every four batteries globally, and it is also the largest BESS market. The Chinese government places weight on the role of ESS in the transition to renewables. In Sept., the National Development and Reform Commission (NDRC) announced the "2024–2027 new power system development acceleration strategy," which leverages BESS and supports domestic production and rollout. The plan is to invest about 250 billion yuan (about 52 trillion won) by 2027 to expand BESS capacity to 180 GW. That is nearly double the current storage capacity (95 GW). The United States is also seeing rapid BESS growth centered on states such as California and Texas. After California experienced a major blackout in Aug. 2020, its battery storage capacity more than tripled to 13 GW. It plans to add 8.6 GW by 2027. On Apr. 30 last year, it generated 7,046 MW for several minutes, an amount comparable to the output of seven large nuclear power plants. According to S&P Global, U.S. battery storage capacity jumped 63% in the first half of this year.
The European Union (EU), the United Kingdom, Australia, Japan, Canada, and Saudi Arabia are also regions where installations are growing sharply, buoyed by government support policies, procurement by public service providers, and power market dynamics. According to the Financial Times (FT), "giga-scale battery farms" made by consolidation of batteries increased from one worldwide in 2022 to 42 this year. Another 250 are expected within the next two years. China is leading many of these projects. In addition to BYD's 12.5 GWh energy storage project in Saudi Arabia, CATL is pursuing a solar storage project in Abu Dhabi, United Arab Emirates (UAE), with 19 GWh of storage capacity, aiming to start operations in 2027.
Korea's ESS expected to be a new growth pillar for K-batteries
According to global battery research firm Rho Motion, among the global top five BESS corporations in the first half of this year, all except No. 2 Tesla (United States)—Sungrow, CATL, CRRC, and BYD—are Chinese corporations. Korea, which once formed the leading group in EV batteries but was overtaken by Chinese corporations, has also been outpaced by Chinese corporations in ESS batteries. K-batteries, which once ranked No. 1 in new ESS builds, shrank as a boom in ESS construction faded after a series of fires from 2017 to 2019.
But the sector is regaining momentum this year as the government pursues a policy to create large-scale ESS complexes. The project will install a total of 540 MW of ESS in North Jeolla, South Jeolla, Gangwon, North Gyeongsang, and Jeju, with a total investment of 1 trillion won. LG Energy Solution and SK On are promoting lithium iron phosphate (LFP), which has relatively low energy density and a lower risk of fire, while Samsung SDI is pushing a nickel-cobalt-manganese (NCM) ternary approach.
Escalating U.S.-China tensions are also creating opportunities for Korea's ESS. Tesla has sourced ESS batteries from CATL, but the U.S. government's higher tariff on Chinese batteries (rising to 58.4% next year from 40.9% this year) is expected to create opportunities for non-Chinese corporations with factories in the United States, such as LG Energy Solution and Samsung SDI. The Korean government has set a goal of raising the global ESS market share from 15% in 2025 to 35% in 2036. BESS also faces no small number of challenges, including fire risk, disposal of end-of-life batteries, supply chain risks tied to reliance on specific countries like China, and short lifespans. What's needed are long-duration ESS technologies, fire safety, and technologies to predict the lifespan of reused batteries. As the share of renewables increases, storing surplus renewable power will require the ability to discharge for more than 4–6 hours over long durations, and some expect that supplying power to AI data centers will require long-duration ESS of 12 hours or more.