Amid the growing challenges the world faces due to climate change, the public’s attention has increasingly shifted towards technological solutions aimed at reducing humanity’s collective carbon footprint. While sectors such as intelligent homes often receive the largest share of the limelight, the regulation of power at its source remains just as important — if not more — to the energy transformation underpinning smart cities.

As governments around the globe continue to increase their use of renewable energy sources, making them more efficient to reduce waste and maintain an adequate supply of electricity has become more important than ever. As most renewable energy sources are dependent on the weather — e.g., sunny days for solar power and sufficient wind for turbines — maximizing their productivity is critical to ensuring a stable grid. Enter intelligent energy storage systems, which can effectively achieve both objectives.

World-renowned power expert addresses energy storage needs
Delta Electronics Inc. is a global leader in power and thermal solutions. It has taken its expertise in the provision of power and applied it to grid energy storage to create a truly comprehensive solution to meet the demands of the real world. Delta has completed dozens of energy storage systems worldwide at facilities such as factories, parks and charging stations.

Fossil fuel-powered generators have nearly instantaneous loads and renewable energy sources can be difficult to control, which can cause large frequency fluctuations on a power grid that can disrupt the stability of electrical supply. In locations with large load variability and rapidly growing adoption of renewable energy sources, it is particularly important to deploy an energy storage system capable of adjusting the frequency during normal operation and responding quickly to emergencies.

Turning Kinmen into a ‘smart grid demonstration island’
Taiwan’s outlying Kinmen Island is mostly dependent on imported fuel to generate electricity. The Tashan Power Plant, built in 1999 and operated by Taiwan Power Co. (Taipower), remains the principal source of electricity for the island’s residents. In mid-2020, Delta completed deployment of a comprehensive solution for the plant’s Xia Xing Power Station.

“Energy storage systems play an important role in Taipower’s plans for building Kinmen into a smart grid demonstration island. We expect this 2MW/1MWh energy storage system will fully demonstrate its capabilities for helping to stabilize the grid,” said Chung Ping-li, president of Taipower.

Featuring lithium-ion batteries with a total capacity of 1 megawatt-hour (MWh), a 2-megawatt (MW) power conditioning system, an energy management system and environment management systems, the Xia Xing project is Taipower’s largest energy storage system. The entire solution was designed, manufactured and deployed by integration specialist Delta, which plans to leverage the experience when constructing smart grids on Taiwan proper.

“Energy systems for the utility segment require rigorous planning and solid technology,” said Cheng Ping, CEO of Delta.

“Under the expert guidance of Taipower, Delta was able to leverage its strengths to make a contribution to Taiwan’s energy transformation,” Cheng said. “Energy transformation is a crucial issue for the development of smart cities.”

High-capacity batteries and power conditioning ensure a secure, stable grid
Delta’s solution can supply about 30 minutes of backup power within 200 milliseconds of an unplanned generator outage — half of the 400-millisecond requirement stipulated by Taipower — as well as regulate fluctuations caused by renewable energy sources to the grid. The high-capacity lithium-ion batteries were manufactured at Delta’s plant in Taiwan. They provide two to four times the discharge power over capacity (2C-4C), allowing them to supply a large amount of power instantly.

Thanks to its bidirectional, megawatt-level power conditioning system and a self-developed energy management system, the system has two operating modes. Normally, the system runs in F-P (frequency-watt) mode to regulate the power grid’s frequency, but it can switch to rate of change of frequency (RoCoF) mode to supply up to 2MW over 30 minutes.

In addition to automatic voltage and frequency regulation, the system also features real and reactive power compensation, and virtual synchronous generator control. Since operations began in January 2020, the system has stabilized the grid during trials of new generators at the power plant and absorbed excess reactive power after transmission lines were moved underground.

Integrated building automation contributes to a comprehensive solution
Delta called upon the expertise of its Building Automation Solutions, Energy Infrastructure and Industrial Solutions, and Energy Storage Solutions units for the Xia Xing project.

To optimize the operations environment, Delta introduced its Internet of Things (IoT) building automation solutions to monitor and control the facility’s air-conditioning, lighting and fire-prevention systems, as well as water accumulation detection, into a centralized management platform.

Smart LED streetlights equipped with IP cameras were also deployed at the facility and its surroundings. If the system detects abnormal access to the site, it automatically alerts administrative personnel for an immediate response.

SELLING POINTS

• High-capacity lithium-ion batteries provide a total of 1MWh of storage and two to four times the discharge power over capacity (2C-4C)
• Integrated 2MW power conditioning system and energy management system allows two modes of operation: frequency-watt (F-P) and rate of change of frequency (RoCoF)
• About 30 minutes of emergency power furnished within 200 milliseconds of unplanned generator outage
• Central management platform allows for monitoring and control of air-conditioning, lighting and fire-prevention systems
• Smart LED streetlights equipped with IP cameras provide automated notification of unauthorized access