B. BILGUUN: THE NEW BATTERY ENERGY STORAGE STATION BOOSTS MONGOLIA'S RENEWABLE ENERGY TRANSITION

A. Khaliun

The government has acknowledged the necessity of an energy transition and has initiated several renewable energy projects. In the initial phase, the First Utility-Scale Energy Storage Project has been launched.

In August 2022, Prime Minister L. Oyun-Erdene and representatives from the energy sector, including the Minister of Energy, participated in the foundation stone laying ceremony for the battery energy storage station project. In December of the following year, the station commenced operations, supplying energy to the central grid. Project Engineer B. Bilguun elaborated on the station's efficiency, built within the project's framework.

What amount of energy is stored and supplied to the central power grid by the Battery Energy Storage Station constructed as part of the project?

The global trend is shifting towards battery energy storage systems as part of the transition to renewable energy production. The stability and reliability of electricity generated from renewable energy sources need to be regulated. This can be achieved through either hydroelectric power or battery storage. Among these options, battery storage stations are considered the fastest, capable of maneuvering in just 1-2 seconds, showcasing advanced technology. Currently, several new projects for the construction of battery energy storage stations are underway.

As part of our project, an international open tender was conducted to select a contractor responsible for designing, supplying, constructing, and implementing an 80 MW power and 200 MWh energy storage facility, along with providing operational support for the first two years. The joint consortium of China's Jiangsu Zhongtian Technology Co., Ltd (ZTT) and Zhongtian Energy Storage Technology Co., Ltd (ZEST) emerged as the successful bidder, securing a 'turnkey contract and commencing construction. Germany's RWE Technology International GmbH served as the project consultant.

The project was funded through soft loans from the Asian Development Bank, with a contract amount totaling $80.9 million. Additionally, the Government of Mongolia provided support by granting exemptions from customs taxes and VAT. Consequently, the battery energy storage station, boasting an 80 MW capacity and a storage capacity of 200 MWh, has been successfully completed and commenced operations.

What is the total energy supplied to the central system since the plant began operations?

The station supplied 17.7 million kWh of energy between December 8, 2023, and April 1, 2024. With a capacity to supply 58 million kWh per year and an average of 4.8 million kWh per month, it consistently meets demand. However, during the peak load in March last month, it exceeded expectations by supplying 5.7 million kWh of electricity.

The battery energy storage station represents a novel and innovative addition to our country's energy sector. What was the primary purpose behind its establishment?

The project aims to address unexpected power shortages within the central power grid, regulate frequency, provide 80 MW of power to the system during peak loads, decrease reliance on energy imports, and promote the integration of renewable energy sources.

Considering the consumption patterns in our country, electricity demand surges significantly during morning and evening hours. As a result, the station is scheduled to charge during the night and operate at a capacity of supplying up to 80 MW of energy to the system during these peak hours. This strategy has been consistently implemented since last December.

Has the station received approval from the State Commission?

Energy supply to the central system commenced in December 2023. We anticipate handing it over to the State Commission in May-June 2024.

How many facilities were constructed as part of the project?

Construction work in the Emeelt area of the Songinohairkhan district has been finalized. The project encompasses seven facilities, comprising a station control building, two 100 MWh transformers, and 32 cold storage facilities equipped with 64 containers. The battery energy storage station is integrated with the Songino substation, which, in turn, is linked with Erdenet, Thermal Power Plant-3, and Mandalgobi city in Dundgobi aimag to the south.

Hence, the proximity of the battery storage station to the power source was imperative to ensure the reliable functioning of the power plant and mitigate the risk of shutdowns during peak loads. To achieve this, the station is interconnected via the Songino substation, with provisions in place to mitigate power shortages and unexpected outages at the Thermal Power Plant-3 station.

If one transformer fails, the other will operate to ensure reliability. The station commenced operations on December 6 and began supplying electricity to the system on December 8. Last winter, during peak hours, it compensated for power cuts in Ulaanbaatar, consistently supplying 80 MW. When renewable energy was available, there were no power cuts; however, in its absence, energy distribution faced limitations. Last winter, we operated effectively under these conditions.

Could you please elaborate on how the concept of frequency regulating functions within the power system?

I want to emphasize that this battery energy storage station is designed to address sudden power shortages within the integrated grid. Its purpose is to ensure system stability, facilitate frequency regulation, provide up to 80 MW of energy during peak times, and decrease reliance on imported energy.

Frequency regulation refers to the modulation of frequency in response to fluctuations in power demand. When consumption rises, frequency drops, and when consumption falls, frequency increases. The battery energy storage station can swiftly react to drops in frequency caused by heightened consumption.

It is deemed superior to water charging stations due to its rapid response capabilities. With the ability to receive and execute commands swiftly, it can provide or stop 80 MW of power in less than a second.

We've observed that while a hydroelectric olant requires a significant construction period, a battery energy storage plant can be erected relatively quickly. We initiated earthworks for the station in April 2023 and the station was already commissioned in December 2023, demonstrating a notably shorter construction timeline.

How will the battery energy storage work together with renewable energy sources?

The advantage of a battery storage station lies in its potential to substantially bolster supply when charged from renewable sources. Given the lack of regulating mechanisms, relying solely on renewable energy for consistent system operation is impractical. However, with the integration of a battery energy storage station, we can augment renewable energy production and enhance system reliability.

This capability enables the plant to store excess energy when production surpasses consumption-a significant advantage with the potential to substantially reduce CO2 emissions.

The government has set a achieving 30% renewable energy sources by 2030, with current levels at approximately 17-18%. However, one of the challenges stems from the unpredictable nature of target of Mongolia's environment, posing risks to renewable energy production. Addressing this challenge requires adequate calibration stations.

An automatic setting is in place to promptly cut off consumption from the Russian import line if it exceeds 310 MW. The presence of a battery storage station significantly aids in addressing such outages.

If your station has the capacity to store and supply 58.5 million kWh of energy annually, what magnitude of load can it accommodate?

If the average monthly household consumption is 250 kWh, totaling 3,000 kWh annually, our battery energy storage station can be considered capable of supplying electricity to approximately 20,000 households per year.

The battery energy storage station represents a novel technology in our country. Consequently, as part of the project, efforts are underway to develop regulations and methodologies for tariff calculations aligned with international standards. We are collaborating with the working group established under the Ministry of Energy in this endeavor. Additionally, we are partnering with international specialized organizations to establish and refine regulatory frameworks. The sectoral Ministry will provide further information on approval timelines and tariff specifications.