ESS: A Power Source for Enhancing Renewable Energy Stability
23 September 2024
As the global community sets a common goal to reduce carbon dioxide emissions to help slow down climate change, renewable energy has become one of the primary options many countries are focusing on. Not only is it clean and environmentally friendly, but it also offers low-cost electricity generation, as it comes from nature and is inexhaustible. However, it is important to remember that renewable energy cannot generate electricity continuously. To address this, the Electricity Generating Authority of Thailand (EGAT) has developed Energy Storage System (ESS) to provide backup when the sun is not shining or the wind is not blowing. This article will show how ESS supports and enhances the stability of renewable energy.
BESS: Fast-discharging, Highly Flexible Battery to Maintain Power System Stability
Battery Energy Storage System (BESS) stores excess power of the system and supplies it when needed. As it discharges power quickly, it helps enhance the stability of the power system. EGAT has installed grid-scale BESS to manage fluctuations of renewable energy in certain areas, such as Chai Badan Substation in Lop Buri Province (21 MWh) and Bamnet Narong Substation in Chaiyaphum Province (16 MWh). Moreover, to maintain power system security in remote areas, EGAT has installed a 4 MWh BESS as part of Smart Grid Pilot Project in Mae Hong Son Province to store electricity generated by a solar farm and supply it during power outages in the area.
Pumped-storage Hydropower Plant
The pumped-storage hydropower plant is a type of energy storage system, often referred to as a large hydropower battery. It can supply power to the system quickly, second only to BESS. When more power is needed for the system, the pumped-storage hydropower plant will release water from the upper reservoir to spin the turbines for generating electricity. The released water is then stored in the lower reservoir. During periods of low power demand, the excess electricity is used for pumping the water back to the upper reservoir for future electricity generation. Presently, EGAT operates three pumped-storage hydropower plants: Srinagarind Dam in Kanchanaburi Province (360 MW), Bhumibol Dam in Tak Province (171 MW), and Lamtakong Jolabha Vadhana Power Plant in Nakhon Ratchasima Province (1,000 MW). Moreover, EGAT is developing a similar project at Chulabhorn Dam in Chaiyaphum Province (800 MW), which is planned for commercial operation in 2034.
Hydrogen Fuel Cells: Clean Energy of the Future
To achieve a low-carbon society, hydrogen is one of the interesting options as it can be extracted from various natural materials. When burnt, it produces only water and oxygen, making hydrogen a sustainable and efficient clean energy. Currently, EGAT can produce hydrogen from wind energy. The electricity generated from wind turbines is stored in the form of hydrogen (Wind Hydrogen Hybrid System), which is paired with a 300 kW fuel cell to convert hydrogen back into electricity supplied for EGAT Learning Center – Lamtakong in Nakhon Ratchasima Province. Additionally, EGAT is studying the conversion of lignite into hydrogen for power generation with fuel cells at Mae Moh Power Plant in Lampang Province. This process is expected to have a generation efficiency more than twice that of the current system. Beyond energy storage, hydrogen can be blended with conventional fuels to reduce the use of fossil fuels. EGAT is now exploring the use of hydrogen mixed with natural gas as an option to further reduce greenhouse gas emissions in the power generation sector.
The new Power Development Plan (PDP2024), expected to be announced in September, sets the share of electricity from renewable energy at 51%, reflecting a complete transformation of the future power system. However, the security of the power system must be maintained. Various types of Energy Storage System will be a critical puzzle piece in ensuring the stability of the power system, supporting Thailand’s journey toward Carbon Neutrality and Net Zero Emissions.