Artificial intelligence (AI) data centers are broadening the investment landscape for the power storage industry. While expanded demand for energy storage systems (ESS) driven by data center build-outs had been a key point in the investment market, interest is now shifting to in-server "backup power sources," such as supercapacitors (EDLC), that resolve millisecond (ms)-level rapid power fluctuations arising during computation.
As Big Tech's race for AI leadership intensifies, AI data centers have expanded rapidly, centered on the United States. The global data center scale is estimated to have increased from about 36 gigawatts (GW) at the end of 2022 to 62 GW at the end of 2025. In particular, the share of investment in the United States surged about 96% over the same period, becoming the axis of growth.
Investment in U.S. data centers is leading to high growth in ESS. Because nuclear and large gas power facilities take more than five years to build, ESS has emerged as an alternative to meet surging power demand. U.S. power generation capacity jumped from 13.5 GW in 2022 to 40.5 GW in 2024.
Market attention is recently moving from ESS to in-server backup power sources such as EDLC. Unlike general data centers that use central processing units (CPU), AI data centers see power demand spike sharply on a millisecond (ms) basis as graphics processing unit (GPU) clusters carry out training and inference. If this power load is not addressed, power inefficiencies arise.
In response, Big Tech is focusing on building multi-layered storage architectures that supply instantaneous power and stabilize voltage and frequency by using BBU (Battery Backup Unit), lithium-ion capacitors (LIC), and EDLC. BBUs supply power for several minutes in emergencies such as outages until backup generators start, while LICs and EDLCs respond to rapid load changes on the order of around one second.
Jang Jeong-hun, a Samsung Securities researcher, said, "The biggest problem AI data centers face is 'load reflection,' in which GPU chip power demand spikes sharply on a millisecond basis," adding, "BBUs and supercapacitors installed inside server racks will immediately supply momentary peak power and improve power operability."
Domestic supercapacitor companies include VINATech and LS Materials. According to Samsung Securities, VINATech is estimated to have signed a contract in May 2025 to exclusively supply supercapacitors for emergency power to Bloom Energy's fuel cell project.
LS Materials does not yet have AI-related revenue, but in Sep. 2024 it signed an MOU with Vertiv, a major partner of Nvidia and a global data center power solutions corporation, to supply supercapacitors (marketed as ultracapacitors, or UC) for AI data center UPS.
Cho Hyun-yeol, a Samsung Securities researcher, said, "Compared with general data centers, AI data centers are seeing more rapid power fluctuations, leading to a trend of adding not only BBUs but also UCs in multi-layered storage structures," adding, "In particular, when 800V DC data centers are introduced, the need for buffers between upper and lower power stages will grow, and UCs are increasingly likely to play that role."