The Energy Storage System at the Salt Field Solar PV Farm in Tainan
In conjunction with the government's promotion of solar power generation combined with energy storage system installations, Taipower aims to improve the resilience of its power system and increase the penetration of renewable energy. In 2020, Taipower partnered with renowned renewable energy company United Renewable Energy Co. to establish the Salt Field Solar PV Farm in Tainan, which became the country’s largest demonstration site for integration of solar power and energy storage. On June 30, 2022, the plant successfully connected to the grid, with a capacity of 20 megawatts (MW) and a total energy storage capacity of 20,000 kilowatt-hours (kWh). At the time, the achievement set the record for the largest energy storage system in Taiwan and was capable of providing one hour of electricity to 40,000 households.
Borrowing Light from the Sky to Illuminate the New Glory of the Salt Fields
Tainan receives more than 2,100 hours of sunshine annually, with even stronger sunlight along the coastal areas. In the past, the coastal regions of Beimen and Qigu used the area’s intense sunshine to develop salt production industries. With the passage of time, the vast salt flats in Tainan, which once drove the prosperity of the area, have now become tranquil and quietly serve as detention basins. However, in recent years, Taiwan has actively developed renewable energy and set a goal of achieving a solar photovoltaic installation capacity of 20GW by 2025. This transformation has turned the unused salt flats – those without agricultural or other planned purposes – into sought-after locations for ground-mounted solar power plants. Taipower’s newly constructed Salt Field Solar PV Farm in Tainan restores the area’s former glory by again borrowing light from the sky.
Construction supervision
Construction on this project began in May 2021 and coincided with the rainy season. Drainage was an important issue, so temporary drainage channels were excavated and subsequently integrated with the drainage equipment at the Salt Field Solar PV Farm to minimize the impact of accumulated water. During the installation of the equipment, large lifting machinery had to be employed. From planning and design to construction, each step was carefully supervised by professionals. Eventually, the main equipment's civil engineering foundation was successfully completed in January 2022.
During the COVID-19 pandemic, the transportation of imported equipment and the arrival of technical personnel from original manufacturers was very challenging. Apart from constantly tracking shipping conditions and closely communicating with the Ministry of Foreign Affairs to understand the latest pandemic-related regulations, remote connections were used for pre-installation preparations. Through these efforts, the installation of the equipment was gradually completed, and it was smoothly integrated into the photovoltaic field in June 2022.
Building a sustainable Taiwan through the integration of solar power and energy storage
To assist in maintaining a high-quality, stable power supply for the electrical grid, Taipower is making good use of the land space within the Tainan Salt Field Solar PV Farm . The facility contains a total of eight energy storage containers that use lithium-ion batteries and are each capable of storing 2.5MWh of electricity. In total, the storage system can store approximately 20MW, which, if discharged entirely within one hour, can provide electricity for around 40,000 households.. The energy storage system can discharge power immediately to fill any power gaps, and its hour of duration provides enough time for all the natural gas units across Taiwan to start up and restore power. It is anticipated that similar energy storage facilities will be gradually established throughout Taiwan in the coming years. Apart from addressing the impact of intermittent energy sources on the power system, these storage systems will also allow excess solar power generated during the day to be stored and discharged during the peak electricity demand period at night. This will help enhance the stability and proportion of solar power generation, increase power dispatch flexibility, and significantly reduce voltage fluctuations caused by various unforeseen events.
Environmentally friendliness
The project site provides clean renewable energy through two different modes: ground-mounted and water surface-mounted PV equipment. This required the installation of nearly 40,000 precast concrete piles that elevate the solar panels by 2.1 meters. During the planning phase, the pre-existing function of the salt flats as a detention basin was preserved, and a buffer green belt was created to provide a bird-friendly habitat. Considering the nearby wetlands are environmentally sensitive, sensitive zones were avoided during site selection. In compliance with the building coverage regulations, 30% of open space was preserved. The module frames were arranged with color contrasts resembling the salt flats and flatfish, creating a tourist and recreational destination that balances both power generation and ecological sustainability while preserving the integrity of the wetland ecosystem.
Future prospects
Currently, energy storage relies heavily on foreign equipment suppliers. Regarding the risks, safety, and maintenance strategies during operation, Taipower will enhance employee education and training to increase the relevant capabilities of its personnel. Furthermore, the experiences gained at the Tainan facility will be fed back into the design of future projects to ensure smoother construction processes.
Taipower plans to install a 2MW energy storage system at the Changgong Wind Farm and, in doing so, will rely heavily on the experience gained with energy storage implementation in the Tainan salt flats. This will ensure that the project is completed on schedule and at a high quality. The Changgong project will be the first demonstration site in Taiwan that combines wind power with energy storage.