Energy Storage System Boosts Reliability in Illinois

Ameren Illinois’ line crews traverse rough and hilly terrain and flood-prone regions to keep the lights on for the 145 customers in Thebes, Illinois. A 69 kV power line runs through a national forest in southwestern Illinois to power the village near the Mississippi River.

Due to the remote nature of the service territory, the linemen often face challenges when patrolling the area and repairing line damage. For example, a crew recently responded to an outage caused by a tree that was off the right of way, which landed inside the right of way, damaging an H-structure spar arm.

To improve power reliability in the region, the line crews implemented several different projects. For example, the linemen storm-hardened three miles of the 69 kV pole line to fortify and enhance structures. In addition, the crews replaced non-SCADA-controlled 69 kV air break switches with SCADA controlled switches as well as deployed a fault locating, isolation and system restoration (FLISR) control system to enable auto sectionalization of the line and expanded right-of-way widths to enable additional vegetation management trimming.

Installing the Battery System

To further boost reliability, Ameren Illinois installed a new battery system for the village of Thebes, Illinois. The first step was to prepare the site, which included grading and graveling the energy storage site and performing preliminary engineering for circuit modifications necessary to enable the project.

Next, the contractor construction crew poured the foundations to accept the hardware, which included the energy storage container, step up transformer, low-voltage switchgear and metering cabinet. The process of installing the energy storage container required a specialized crane with capabilities to lift and position it in place.

The battery, electronics, fire suppression and inverters were assembled into the storage container in the S&C Electric factory in Franklin, Wisconsin. S&C and Ameren Illinois personnel then tested it as a complete unit. S&C then removed the lithium-ion batteries and shipped them separately along with the container to Thebes, Illinois.

Once all the equipment arrived on site, the crews installed the hardware on their respective foundations as well as installed 168 battery modules inside the energy storage container. An electrical contractor then installed the low voltage interconnection wiring between the battery storage system components and the utility padmount transformer.

Then the Ameren Illinois line crew installed the in-line SCADA controlled distribution circuit recloser to establish the isolation point when loss of supply is experienced to allow the energy storage or battery system to restore customer service. The recloser also enables the primary feed to be re-established once the supply is restored.

Next, Ameren Illinois Distribution Automation technicians installed wireless communications and performed commissioning and operational checks to place the equipment into service.

Overcoming Challenges

From start to finish, the construction process took about six weeks. The site preparation began in November and the energy storage system was commissioned in late December.

During the construction project, the main challenge was the container lift and placement. This process required a specialized crane able to handle very heavy equipment. Ameren Illinois crews had to navigate this crane on narrow roadways through the small local community. Due to the nearby overhead distribution lines, the crews also faced challenges with the lift itself.

“This crane mobilization and lift were both successful but required different approaches that were not originally planned for,” said Chad Raley, manager, Renewable and Technical Business Development, Ameren.

In addition, commissioning testing as well as ongoing operational challenges represented major learning opportunities with this project. Several changes to the systems’ electronics settings were implemented over a 24-month period in order to fine tune the operating parameters, which allowed the system to automatically restore (black start) electric service to Ameren Illinois customers upon loss of electric supply.

“Being able to quickly respond to system alarms and make equipment repairs proved challenging due to the remote location of this battery installation in southwestern Illinois,” said Troy Tipsword, superintendent, Distribution Automation, Ameren Illinois. “Our team also showed great resiliency when we had to replace a portion of the battery due to a decision by the manufacturer.”

As the second installation of energy storage and energy storage electronics systems, Ameren Illinois included an operations and maintenance contract for the complete system. The vendor maintains the system on a regular basis along
with support from Ameren Illinois’ Distribution Automation department.

Given the technical nature and complexity of the batteries and battery electronics (controllers/inverters), LG, the battery system manufacturer, provides support as needed. For example, Ameren Illinois has experienced a battery replacement through the warranty since the unit was installed. Also, the battery and electronics system is monitored in real time by S&C Global Monitoring, and Ameren Illinois is notified of any
maintenance or operational issues.

Finally, Ameren Illinois Distribution Control Office has Systems Control and Data Acquisition (SCADA) visibility into the Energy Storage system, which includes the ability to manually operate portions of the system as well as enable system automation.

Moving Forward

The new energy storage or battery system, coupled with the distribution automation controls and equipment, provides the opportunity for Ameren Illinois to restore customer power when the local power supply is interrupted. Due to the remote nature of the terrain and electric infrastructure in this part of the Ameren Illinois service territory, this restoration capability improves the potential reliability for these customers.

“Most importantly, customers on this circuit are experiencing fewer and shorter outages,” said Jason Klein, director Division VI Operations for Ameren Illinois. “We have received positive feedback from our customers and the community on our efforts to test this new technology and maintain our facilities.”

As part of Ameren Illinois’ Downstate Clean Energy Affordability Act, Ameren Illinois proposes to install new energy storage systems along with deployment of renewable energy generation infrastructure such as solar in other parts of its service territory.

The village of Thebes, Illinois, was selected for the energy storage project due to the challenging environment as well as the numerous improvements executed to enhance customers’ reliability metrics.

“Successfully restoring electric service under a black start condition demonstrates that energy storage systems can improve customer reliability,” said Richard Mark, chairman and president, Ameren Illinois. “Moving forward, we’ll continue to test these storage systems to ensure that they can handle the variability we experience in customer load. This data will help inform future installations of energy storage systems throughout our service territory.”