The Florida Public Service Commission, in a recent “notice of proposed agency action order”, approved Tampa Electric Company’s (TECO) petition for approval of standard interconnection agreements for interconnected customer-owned battery subsystems.
The commission’s action is preliminary in nature, according to the filing, which also noted that any person whose substantial interests are affected by the proposed action may file a petition for a formal proceeding. Such petitions were due to the commission clerk by March 15; in the absence of such a petition, the order is to become final, the filing noted.
As noted in the order, TECO last December filed its petition for approval of a standard interconnection agreement for interconnected customer-owned battery subsystems. While styled as a petition for a single interconnection agreement, TECO’s petition seeks approval of two new interconnection agreements: one for customers owning property where battery subsystems are connected (referred to as the Owner’s Agreement), and one for customers renting property where battery subsystems are located (referred to as the Renter’s Agreement).
The commission added that the Renter’s Agreement includes signature blocks for the utility and the renter and puts the renter on notice about the Owner’s Agreement. The Owner’s Agreement and Renter’s Agreement – collectively, referred to as the agreements – are intended to facilitate the interconnection of customer-owned and customer-rented battery subsystems that are located behind the customer meter but are connected to, and operate in parallel with, TECO’s electrical grid.
The commission also noted that in the Owner’s Agreement, a battery subsystem is described as a battery system consisting of one or more storage batteries and battery chargers – including inverters, converters, and associated electrical equipment; that includes batteries charged by solar photovoltaic arrays.
Those battery subsystems will supply power only for the customer’s own use and will not export power onto the utility’s supply grid for more than 100 milliseconds, the commission said.
During a faulted condition on the utility’s system, the customer’s battery subsystem will be isolated but it will still be able to provide electricity to the customer. The commission added that a faulted condition can occur for reasons such as contact with vegetation, lightning, weather, animals, or vehicles.
The utility currently anticipates interconnecting 73 customer-owned battery subsystems and the Owner’s Agreement will allow the safe interconnection of those subsystems.
The commission added that as long as the customer’s interconnection complies with the provisions set forth in the Owner’s Agreement, the utility does not expect any negative impacts to its electrical grid. Some of those provisions include requiring the customer to have the battery subsystem inspected and approved by the authority having jurisdiction and providing proof of that inspection and approval to the utility; requiring the customer to maintain the specified amount of general liability insurance for personal injury and property damage; and requiring the customer to install an isolation switch to allow the utility to completely separate the battery subsystem from the utility’s system, if necessary, for safety purposes.
The commission added that the provisions of the Renter’s Agreement notify the customer renting property where a battery subsystem is located that the owner of the property remains responsible for all provisions in the Owner’s Agreement that the owner signed with the utility. The Renter’s Agreement also requires the customer to abide by, and comply with, all applicable provisions of the Owner’s Agreement that relate to safety and that govern the use, operation, and maintenance of the battery subsystem.
By complying with the agreements, ratepayers owning battery subsystems and renting property where battery subsystems are located can safely interconnect and operate in parallel with the utility’s electrical grid, the commission said. Under the Owner’s Agreement, operation of the battery subsystems in parallel with TECO’s electrical grid is not permitted unless the specified requirements are met. Therefore, the commission added, the Owner’s Agreement will facilitate customers’ desires to own and operate battery subsystems and the utility personnel working at or near the premises will benefit from the safety measures included in the Owner’s Agreement.
The required installation of a visible isolation switch helps to ensure that the battery subsystems are operated in a safe manner by allowing the utility to open the switch under necessary conditions, the commission said, noting that conditions which may require the switch to be opened include utility system emergencies or maintenance requirements.
Under the Owner’s Agreement, the customer agrees to permit the utility to inspect the battery subsystem and its components as well as the required documentation, before and after the battery subsystem goes into service, and to witness the initial testing of the customer’s battery subsystem, if the utility chooses, the commission noted. Once the utility has received written documentation from the customer that the requirements of the Owner’s Agreement have been met and the correct operation of the isolation switch has been demonstrated to a utility representative, the utility will send a written notice within 10 business days that parallel operation of the battery subsystem can begin.
“We have reviewed the agreements and find that the provisions of the agreements are reasonable and are in place to protect the ratepayers as well as the utility personnel,” the commission said.