The 1MW/1MWh energy storage system created by the one-stop service (including investment benefit evaluation, customized solution planning, construction, orientation and training) allows National Changhua University of Education (NCUE) to not only stabilize the grid and regulate electricity, but also to optimize contract capacity to reduce waste and penalty charges while deepening academic research on microgrid and intelligent energy.
Project Background
Increasing environmental awareness has led governments to formulate policies promoting green energy. In recent years, Taiwan has amended its Renewable Energy Development Act to encourage the adoption of green energy. The act sets requirements for large electricity consumers with a contract capacity of more than 5 MW, requesting that they choose one of four options: building green power, implementing an energy storage system, purchasing a renewable energy certificate, or paying an energy levy. The main reason for listing the energy storage system as an option is because it not only helps dispatch power and alleviate tight power supply during peak hours, but it also regulates the power grid, provides backup power, and promotes auxiliary solar energy sources.
Taking schools, factories, hospitals, industrial parks, and other large electricity consumers as an example, they have all signed a power capacity contract with the Taiwan Power Company (Taipower). A sizeable problem they must face because of this is that power consumption may exceed the contracted capacity during peak power periods or when seasonal surges in power demand occur. Once the contract capacity is exceeded, a penalty charge applies, and this is several times their regular electricity rate.
Another problem is that the contracted capacity is fixed, but electricity demand tends to fluctuate and is virtually impossible to predict with 100% accuracy. Hence, even if electricity consumption is lower than the contracted capacity, the charge remains in accord with the contract, commonly resulting in unused overpayment.
Some users have adopted diesel generators as an emergency power source so as to avoid the inconvenience caused by sudden power outages. However, generating electricity with diesel produces pollutants that are harmful human health and the environment. Furthermore, maintenance of diesel generators is not easy. In the case that generators are not properly maintained regularly, they may malfunction and thus cannot be used in an emergency.
To this end, energy storage systems that offer both timely regulation and emergency backup power features have become the only choice to meet the requirements of legislation aimed at large power consumers. The fact is that they lower the risk of penalty charges and unused overpayment and are an ideal replacement for diesel generators as a source of backup power.
Project Requirement
NCUE is a well-known institution in central Taiwan. Its College of Engineering and College of Technology have deep strengths in power research and commitment to academic research on intelligent energy, microgrids, and green energy development. Recently, they received a donation from Ørsted, the global offshore wind power leader, to build a megawatt-level energy storage demonstration system on the Baoshan Campus as an application and experimental environment for teacher–student project research.
In addition to the training of grid talents, a part of developing this energy storage system includes the task of optimizing the contract capacity of NCUE’s Baoshan Campus. NCUE hopes to regulate the difference between day and night as well as seasonal electricity consumption through utilizing the energy storage system for peak shaving and valley filling as well as supplying electricity during peak times. This is aimed at finding the best contracted capacity to save on electricity costs and avoid penalty charges. Meanwhile, the previous practice of using diesel generators as a backup power source can be greatly reduced. NCUE also plans to establish a solar energy system in the near future. At that time, the system will complement renewable energy sources to create a microgrid that can self-generate power for its own use.
In response to the abovementioned requirements, Ørsted has adopted a strict and cautious approach to selecting suppliers and solutions after public bidding. The company details the requirements, such as the energy storage system functions, the battery specifications, and the control interface of the energy management system. The company also aims to have suppliers provide services in a turnkey manner. Therefore, only those suppliers that are able to meet the requirements, including software system and hardware equipment, on-site installation and construction, and Taipower on-grid testing, will be selected.
System Introduction and Product Offerings
Delta is one company to have been selected by Ørsted to provide complete solutions and services. After winning the bid, Delta obtained NCUE’s annual electricity consumption data and used self-developed investment benefit evaluation software for energy storage systems to carry out a load and electricity analysis. Based on the historical data, the software simulated the benefit of using energy storage systems for peak shaving and valley filling and estimated in advance how much electricity cost and return on investment (ROI) can be saved after system implementation. This enabled planning out the most suitable energy storage system solution for NCUE.
After completing the simulation and evaluation, Delta proposed the following solution according to NCUE’s requirements:
PCS1000: This power conditioning system has a capacity of 1 MW and provides bi-directional power conversion for power dispatching, as well as control and regulation between battery energy storage and power grid and load;
BESS: This battery energy storage system is equipped with an FM200 automatic fire suppression system and is a highly integrated system that provides multiple layers of safety protection mechanisms. It can also accept batteries from various manufacturers;
EMS: This energy management system provides multiple control modes and monitoring information through a web-based interface, allowing for remote management;
Peripheral facilities: These include a 11.4-kV PT/MVCB panel, 380-VAC MP/MR panel, and transformer;
Customized service: Configuring cameras and RFID access control systems at the installation site enables the use of passwords and cards to manage access, effectively allowing a monitoring center to be set up in the Engineering Building for administrators to operate the system from the office and monitor the on-site status.
The solution provides many practical functions. Three featured functions are meter tracking, load shifting, and integrated distributed energy resources.
Meter tracking can be used to set the upper limit of power consumption, allowing the energy storage system to charge and discharge batteries to optimize power consumption and cost without exceeding the contracted capacity or breaking related conditions. In other words, the system can track meters on the grid side and load side under the condition that total power consumption is maintained at a preset value. When power consumption is high, the energy storage system can deliver power to support the grid and thus prevent the usage from exceeding the contracted capacity and resulting in penalty charges. When power consumption is low, the energy storage system can make full use of the contracted capacity to charge, thereby reducing the risk of unused overpayment.
Load shifting is used to balance peak and off-peak power consumption. This function was specifically built for NCUE. Based on its load operation mode, NCUE can use the energy storage system to support electricity when power demand is high during the day, while using grid power to charge the system at night when electricity costs are low.
Integrated distributed energy resources involves using the energy storage system as the dispatching core of the microgrid to centrally regulate multiple power sources and loads. For NCUE, its current power sources are grid power and diesel generators. When the solar system is completed in the future, the energy storage system can be used to optimize dispatching and regulate the three power resources.
Conclusion
Delta’s energy storage system is a multi-purpose solution. In addition to Delta’s efficient solutions for energy control, the company also offers complete services, including initial power usage modelling and cost-saving evaluation, solution planning, on-site construction, customization, orientation and training, and localized after-sales services. Delta can meet the needs of customers and can help large power users who are not specialized in power plants to manage energy storage systems under safe conditions, so as to maintain the highest availability of system operation.
Additionally, Delta has a wealth of practical experience in Taiwan and abroad. In recent years, the company has completed construction of energy storage systems used in more than ten application fields, including battery factories, electronic component factories, automation factories, plant factories, energy-saving parks, microgrids, solar power plants, electric locomotive charging stations, and commercial buildings. Construction of these systems has been completed and all are currently in operation.
The current project has passed the 120-hour uninterrupted stability test after completion. It has also passed a number of inspections, such as Taipower’s grid connection and fire safety tests. It was officially launched at the end of 2019 and is currently managed by NCUE. In addition to the system’s smooth operation, its effectiveness is also becoming increasingly apparent. The system will continue to play a demonstrative role in energy conservation and research, and will provide a critical contribution to Taiwan’s energy transformation.