China Huaneng UK Mendy battery energy storage project is currently one of the largest grid-side single battery energy storage power stations in the UK and even Europe, and it is also the first large-scale battery energy storage project built by a Chinese power company in a developed country. It creates the possibility for the power grid to absorb more renewable energy, and it also takes care of the surrounding beautiful ecological environment in every possible way during the construction and operation process.

The Mendy Project is located 140 kilometers west of London, England, near the town of Mendy in Wiltshire. Wiltshire is the second largest province in the UK for solar development. The installed capacity of the project is 99.8 MW, and the total energy density is 99.8 MWh (single charge and discharge takes 1 hour). It consists of two 49.9 MW battery energy storage station areas in the north and south.

The Mendi project is invested and constructed by Huaneng Hong Kong Company and Guoxin International in a ratio of 51:49. The construction started in December 2019 and will be officially put into commercial operation in July 2021. The main equipment of the project is manufactured and integrated by Chinese companies, and it mainly participates in services such as peak shaving, fast frequency response, balancing mechanism, and capacity market in the UK grid, creating conditions for the UK grid to absorb more renewable energy and helping the UK achieve net zero emissions by 2050 plan.

Mendy project panorama

In recent years, the proportion of renewable energy power generation in the UK has continued to increase. Renewable energy such as solar energy and wind power is intermittent, which also poses a great challenge to the stable operation of the power grid. To absorb more renewable energy power generation, the grid must have more capacity for instantaneous frequency regulation and peak regulation. The construction of battery energy storage projects that can quickly participate in frequency regulation and peak regulation has become one of the important ways to improve the flexibility and security of the power grid.

Since entering the UK market in 2011, Huaneng Hong Kong has actively understood the local power market rules and sought potential project opportunities. In 2017, Huaneng Hong Kong Company keenly anticipated the importance of battery energy storage to the clean development of global energy and the broad development prospects of this technology, and formed a joint working group with Guoxin International to jointly promote the development of battery energy storage projects in the UK. From the end of 2017 to the middle of 2018, after comprehensive analysis and comparison of many project opportunities, the working group finally locked on the Mendy project with the largest scale and the best geographical location.

Mendy Project Battery Container

Since there have been no successful cases of such a large-scale single battery energy storage project before, and relevant industry standards are being gradually improved, Huaneng Hong Kong Company has crossed the river by feeling the stones, formulating project standards, and exploring business models. The project signed the first power purchase and sale agreement for battery energy storage projects in the UK market with Shell European Energy, leading the new development direction of the UK battery energy storage industry. On December 5, 2019, the project officially started. Representatives from the Chinese embassy in the UK, the British Department for Commerce, Energy and Industrial Strategy, the British Department for International Trade and other government departments, as well as business experts such as the National Grid, Southern Scottish Power Company, and Shell European Energy Come to the scene and witness this historic moment together.

Since its completion, the Mendy project has been repeatedly recognized at home and abroad. In January 2022, the Mendy project won the Outstanding Contribution Green Cooperation Award from the Chinese Chamber of Commerce in the UK. In February, the Mendi project was selected as an insight report case of the World Economic Forum "Promoting the Green Development of the Belt and Road Initiative: Playing the Role of Finance and Technology to Promote Low-carbon Infrastructure Construction", explaining how utility-scale battery energy storage technology can make up for the gap of renewable energy Intermittent shortcomings to ensure grid stability.

As of the end of November 2022, the Mendy project has been in safe and stable operation for more than 500 days, providing strong support for the UK dynamic frequency modulation market. Under the global trend of carbon emission reduction, battery energy storage projects may usher in explosive growth in the next five years.Editor/Ma Xue