Drive down the streets in most neighborhoods and you’ll see utility poles and wires that bring electricity to your home, your child’s school and your local grocery store. But did you ever wonder how the power we depend on every minute of every day gets to your neighborhood in the first place?
The answer is the local substation, a collection of transformers, circuit breakers and other equipment that “feeds” power to the wires so that it can be safely used to run your air conditioner on a hot summer day or make ice cubes in your refrigerator.
PSE&G has about 300 substations, critical to delivering power to homes and businesses. Think of a substation as a foundational bridge between the high voltage transmission station and the lower voltage needed to distribute electricity safely to customers. Equipment failures within these substations can lead to outages.
To help reduce the risk of weather-related failures, PSE&G initiated a program to raise and rebuild substations most affected during extreme weather. These highly-efficient, modern substations are helping hundreds of thousands of customers experience fewer storm-related outages.
Redesigned, Compact, High-Tech Substations
Older substations, many built in the mid-1900s, make use of large, outdoor equipment requiring significant space. The equipment also requires regular maintenance to check functionality and prevent outages.
Modern substations are more compact because new equipment is smaller, better insulated, multifunctional and easier to monitor. The equipment is also smart – with sensors and relays that produce rich data, useful for maintenance, planning and outage prevention and recovery.
These vital components are less susceptible to weather damage because they are enclosed in buildings rather than exposed to the elements. Where necessary, new or rebuilt substations are raised above today’s flood zones, at least one foot higher than federal requirements, for added protection.
Each substation is composed of hundreds of parts that must work in harmony to deliver electricity. Since electrical surges and other unwanted events happen, protection and control systems are needed to maintain a safe flow. Modern substations have an advantage in that now equipment can multitask instead of just performing one function, which increases resiliency and leads to faster restorations, among other benefits.
Major Substation Equipment
Substations have the following major components:
- Transformers are the biggest and most expensive equipment in the substation. PSE&G’s largest transformer is just about the same square footage as an average single family home, although much taller. The transformer is the source of power for the connected network of wires and equipment that delivers power to customers. The transformer “steps up” or “steps down” voltage, depending on the need. PSE&G uses substations to step down high voltages — 230 kilovolts, 138 kilovolts, 69 kilovolts and 26 kilovolts — to either 13 kilovolts or 4 kilovolts for safe distribution to customers.
- Circuit breakers are automatic switches that open to stop the flow of electric current at a set voltage, to help prevent major problems. They are similar to the circuit breakers in your home’s electrical panel.
- Current transformers “step down” electric current.
- Disconnect switches separate energized equipment from de-energized equipment, making it safe to perform inspections, repairs and maintenance.
- Protection and control systems have protective relays to control the activation of circuit breakers to isolate troubled parts of the electric network quickly.
- Lightning arresters protect equipment from high voltage surges.
Energy Strong II
In its Energy Strong II proposal currently before the New Jersey Board of Public Utilities, PSE&G prioritized 31 substations for work over the next five years, including 16 at risk of flooding. This plan would build upon the success of the first phase of Energy Strong, which raised, relocated and/or protected 26 switching and substations to benefit 490,000 customers who now experience fewer storm outages.
Also in the works to enhance functionality and resiliency, PSE&G’s next big substation initiative is the touchless substation that will be piloted this fall. It is a substation with many cameras and other digital components, which allow work to happen with fewer visits by humans.