Shire Electric in Rugao, Nantong. [Photo/WeChat account: rugaofabu]

Shire Electric, a company specializing in the power industry in Rugao, has achieved breakthroughs in advanced polymer materials and substation operation and maintenance services, with several of its niche products ranking first in domestic or global market share.

Capsules are critical components in power transformers, with their performance and quality directly affecting transformer operation and service life. Shire's integrated molded capsules have been used in more than 110 countries and regions worldwide, with cumulative applications exceeding 250,000 units across various operating conditions.

In 2025, annual sales revenue from a single capsule production line surpassed 100 million yuan ($14.7 million), while its domestic market share exceeded 80 percent.

Shire has also made a breakthrough in compressed air energy storage, widely regarded as the second major technology route for large-scale, long-duration energy storage after pumped hydro storage. One of the key challenges limiting the development of CAES has been maintaining airtightness in underground cavern systems, where sealing systems must withstand high pressure, high-speed operation, and frequent cyclical changes while remaining stable over decades.

To tackle the issue, Shire assembled a specialized cavern engineering team and developed the world's first polymer steel-rubber composite sealing system.

In December 2025, the sealing system was tested in a large-scale artificial experimental cavern, setting world records by achieving ultra-high-pressure air storage of 18 megapascals and continuous stable operation for 500 hours. The system achieved a daily leakage rate of less than one-thousandth, setting a groundbreaking standard as the first successful implementation of its kind in the world, exceeding expectations.

The sealing system was deployed in May 2026 at the 300-megawatt compressed air energy storage power station in Jiuquan, Gansu province. It is also expected to be introduced in energy storage projects in Dunhuang and Nanyang, providing stronger support for the development of China's energy storage industry.