Enhancing Power System Resilience and Maximizing Green Energy with Microgrids and Distributed Energy Storage

By Xin-En Wu, Mei-Hsu Shih

As the adoption of renewable energy accelerates, the energy transition has become a critical issue. The integration of Microgrids with Distributed Energy Storage is a pivotal topic in this transition, yet it has often been overlooked. During Typhoon Gaemi's impact on Taiwan in August, Microgrids played a significant role in mitigating the Islanding Effect, particularly in mountainous regions prone to severe disasters.

"Participating in Microgrids has been a smooth and natural process," said Kevin Yang, the current Chairman of E.T.T. Storage. "Our initial involvement began during the relief efforts in Xiaolin Village following Typhoon Morakot (88 Flood)[1]. We discovered that solar power systems could aid in the reconstruction of disaster-stricken areas. We leased rooftops in these areas to install solar systems, selling the generated electricity to Taipower and providing residents with rental income while also solving waterproofing and insulation issues. As the number of installed systems grew, we began to encounter challenges in power distribution," Yang explained. Taipower would limit the power output, as an excess of systems in one area could overload the grid, preventing Taipower from accepting all the electricity generated.

Microgrids, as an emerging power system architecture, enhance the stability and autonomy of the power grid. Unlike traditional large-scale power systems, Microgrids can operate independently within a localized area and effectively integrate DERs like solar and wind power. These systems not only maximize green energy utilization under normal conditions, contributing to community RE100 (100% renewable energy), but also maintain local power supply during external grid disruptions through Islanding Operation. This capability is crucial for enhancing power system resilience, especially in the context of current geopolitical and national strategies.

"At that time, we faced the challenge of ineffective power distribution after signing contracts with many Xiaolin Village residents to install solar systems. To address this, we decided to collaborate with the National Chung-Shan Institute of Science & Technology and launched an 'Intelligent Microgrid Demonstration Project,' aiming to improve power distribution through this initiative."

A Symbiotic Relationship between Microgrids and Distributed Energy Storage

When discussing Microgrids, one must first understand the limitations of current solar power systems. "The existing solar power systems have certain constraints," Yang pointed out. Solar power output relies on sunlight, and weather variations cause inconsistent power generation, a characteristic of intermittent energy sources. However, installing solar panels is not a one-time solution; if the grid encounters problems or instability, solar systems are the first to shut down. "All current solar systems are designed with a protective mechanism to stop generating power when the grid is unstable, ensuring the safety of the power system and personnel. This means that if the grid fails, solar power, even if available, will immediately cease."

This highlights the value of Microgrids and Distributed Energy Storage systems. "Storage systems allow users to store excess power during periods of oversupply and release it when the grid is unstable or demand increases, thereby enhancing the stability and reliability of solar power generation," Yang stated. This is the core idea of Microgrids—reducing the impact of the intermittency and instability of distributed renewable energy generation on the operational stability of the power grid. Not only does this achieve efficient decarbonization, but it also realizes stable power supply through a 'dual power system,' which supports the central Taipower grid and even becomes a critical topic in national energy security strategy.

Microgrids Utilize Islanding Capabilities

Yang highlighted the progress made in applying microgrids in Taiwan. The "Sunlight House" Microgrid project by E.T.T. Storage is a successful case in point. This project utilized small-scale solar systems and storage devices to achieve energy self-sufficiency. Solar power first meets local demand in this system, and any surplus is stored in Distributed Energy Storage devices. When external power systems fail, these storage devices can quickly provide power support, ensuring continuity and stability of electricity supply and significantly enhancing the power system's resilience.

"In 2022, Taiwan experienced the 3/15 major blackout, but at that time, the 'Sunlight Xiaolin' and the 'Sunlight House' at the National Science and Technology Museum were the only two residential areas in Kaohsiung that did not lose power. This was thanks to our intelligent dispatch system. Although there was an incident where the system went into protection mode due to seven consecutive days without sunlight, this is also part of the system's design. Taiwan is particularly suited to an energy model that combines solar and storage systems, especially in sun-rich areas like Kaohsiung. Some criticize that solar power doesn't generate electricity at night, and I often joke that if you can make the sun work at night, solar power will follow suit," Yang shared, using real-world examples to demonstrate the importance of Distributed Energy Storage and Microgrids.

"My recent insight is that a threshold is just a door—you can walk out if you open it, but if you're not prepared, it becomes a barrier. Similarly, storage systems will be a threshold for many businesses in the future. If power is unstable and companies are unprepared with storage systems, production will halt," Yang emphasized that Distributed Energy Storage and Microgrids are key to stable power supply. "In Xiaolin Village, we installed independent solar and storage systems for several households, and set up a centralized storage unit managed through an intelligent dispatch system to optimize the use and storage of power."

Pandemic Disrupts Plans but Fails to Slow the Rise of Microgrid and Distributed Energy Storage Development

"About three years ago, we were optimistic about the prospects of the distributed energy storage system market in Taiwan. However, due to the impact of the pandemic, our business model was delayed by three years," Yang further explained. "We originally customized 4,000 energy storage systems for the Tokyo Olympics. To meet Japan's JIS standards, we manufactured six systems and sent them to Japan for outdoor testing, all of which passed. However, due to the one-year postponement and downsizing of the Tokyo Olympics, the initial demand for 4,000 units was eventually canceled. According to relevant clauses, no compensation is required in the event of a natural disaster, and this pandemic was clearly considered a natural disaster."

Although the pandemic disrupted plans, other areas remain full of opportunities. Yang pointed out that UPS (Uninterruptible Power Supply) systems are like the military, ready and waiting, prepared for rare emergencies; whereas microgrid energy storage systems are like the police, constantly patrolling and frequently needing to charge and discharge. "Many sectors that require continuous power support, such as security companies, are now looking to introduce energy storage systems. These systems not only have the functions of a UPS but can also support household electricity during emergencies, such as powering fans or charging mobile phones. The application of these energy storage systems is very broad, capable of meeting various household needs, not just specific UPS requirements."

However, the widespread adoption of home energy storage systems is still limited by the flammability of batteries. For example, systems like Tesla's and those in Japan have been widely used abroad, with most systems installed on external walls or using lead-acid batteries. But in Taiwan, since most families live in apartments, these installation methods are difficult to implement, posing a challenge to the popularization of home micro-energy storage systems.

"The batteries in energy storage systems are flammable, so their use in homes requires particular caution. We are very confident, as we have already advanced these systems into homes and stores, and have made comprehensive plans for power control boards, battery cell selection, and flame-retardant materials. We have implemented energy storage systems in locations such as the Tainan City Government employee dormitories and convenience store warehouses, and they have been very successful," Yang added. He also mentioned that the use of these systems in ordinary households is currently limited because electricity in Taiwan is cheap, but demand will increase if the cost-effectiveness of solar and energy storage systems improves in the future.

E.T.T has not only achieved success in the Taiwanese market but has also begun to expand its services internationally. Last year, in collaboration with local green energy partners, E.T.T successfully entered the Philippine market. They installed the first solar and energy storage microgrid system for a police station in the entire Philippines, located at the Paranas City Government Police Station in Sorsogon Province, southern Philippines. This system is equipped with a 10 kWp solar setup and a 30 kWh lithium iron phosphate battery. It was successfully installed and has been operating stably, providing reliable power autonomy and backup for the city police headquarters.

Yang believes that distributed energy storage systems and microgrids will play increasingly important roles in Taiwan's energy transition process, particularly in addressing "carbon reduction" and promoting "energy digital transformation," the so-called twin transformation. He pointed out that microgrids and distributed energy storage systems can help companies move beyond carbon footprint assessments to effectively achieve energy savings and decarbonization, potentially even securing carbon credits, which can enhance their competitiveness in the carbon trading market. Essentially, carbon footprint assessments are just like stepping on a scale; real decarbonization efforts require establishing distributed power microgrids and storage systems. These efforts enable companies to transform and upgrade, implement energy consumption management, reduce carbon emissions, and meet environmental standards, such as the EU's CBAM and the U.S. CCA.

Yang noted that microgrids can be classified into disaster-prevention, island-type, and community-based. Currently, global trends are focusing on community-based, decarbonized, and independent microgrids. He hopes the government will further relax policy restrictions to encourage more companies and households to participate in the construction of microgrids and energy storage systems. He emphasized that such policy support would help promote energy digital transformation, maximize green energy utilization, and strengthen the power grid, truly achieving the goal of sustainable development. Moreover, this initiative is a key national strategy for advancing data governance, the circular economy, and the application of Web 3.0 blockchain artificial intelligence big data.

Note:
[1]The "88 Flood," also known as the "Typhoon Morakot Disaster," was a severe flood that occurred from August 6 to August 10, 2009, affecting central, southern, and southeastern Taiwan. The primary cause of this disaster was the unprecedented rainfall brought by Typhoon Morakot, with some areas experiencing two days of rainfall equivalent to the total annual average. This event marked the most severe flooding in Taiwan since the 1959 "87 Flood." During this period, widespread flooding, landslides, and mudslides occurred across Taiwan. The most devastating incident was the complete burial of the Xiaolin Village in Jiaxian Township, Kaohsiung County (now Xiaolin Village, Jiaxian District, Kaohsiung City), resulting in 474 people being buried alive.