Korea leads global grid ESS patent filings over two decades

South Korea filed more patents for grid-connected energy storage systems than any other country over the past two decades, the Korea Intellectual Property Office said Monday, with LG Energy Solution the single largest applicant in the field.

Korean applicants accounted for 6,030 of the 14,605 grid ESS patent applications filed with the IP5 group — Korea, the United States, China, Europe and Japan — from 2004 to 2023, or 41.3 percent of the total. China followed with 5,176 applications, or 35.4 percent, ahead of the United States at 1,283, Japan at 1,220 and Germany at 250.

Annual filings in the category grew roughly 125-fold over the period, from 32 in 2004 to 4,010 in 2023, the office said.

Korea also recorded the fastest recent growth, averaging a 68.6 percent annual increase in applications over the three years from 2021 to 2023, ahead of the United States at 53.1 percent, China at 48.2 percent, Germany at 33.3 percent and Japan at 12.1 percent.

LG Energy Solution ranked first among individual applicants with 4,605 applications, followed by China's CATL with 2,653 and Samsung SDI with 242. Four Korean companies placed in the top 10, with LS Electric seventh at 114 applications and Samsung Electronics joint eighth at 78.

Filings were concentrated in safety and management technology — monitoring storage devices and managing heat and fire risks — at 7,705 applications, or 52.8 percent of the total. Long-duration storage accounted for 5,338 applications, or 36.5 percent, and power conversion and grid connection for 1,562, or 10.7 percent.

"The importance of energy storage systems that can store and supply power when needed is growing, in response to the expansion of renewable energy and changes in power demand," said Park Jae-hoon, head of the office's electricity and telecommunications examination bureau. "We will actively support our companies so they can secure core intellectual property more solidly based on the technology development and patent capabilities they have accumulated in the ESS field, and use it to strengthen the foundation for entering overseas power grid markets."