Building for the future, one substation at a time

Since 1860, CPS Energy has provided reliable service to Greater San Antonio. In fact, it’s a responsibility we don’t take lightly. Making sure our customers have electricity when they flip on a switch, turn on an appliance or watch TV is what we pride ourselves on. Naturally, when we plan for the future, we have to be certain that no matter how big our community grows, we have sufficient electricity to serve everyone.

A growing and thriving community is good for the economy, it brings jobs, grows businesses and encourages development of new neighborhoods. Staying ahead of the growth curve is why we have long-term plans. Sometimes this means, looking as far out as 10-20 years to identify where major growth spurts and energy demand is expected.

To beat the population boom, our biggest area of infrastructure expansion comes in the form of substations. A substation is a local power hub or distribution point for electricity. Substations help manage the voltage of our electricity, so it is delivered to our customers at a safe level.  They are typically supplied from a new extension of an existing high-voltage transmission line.

Illustration of how electricity gets from a generation source to homes and businesses.

In our service territory we have 105 substations and 2 more in the planning phase. Our most recent projects include Midtown Substation, just north of downtown San Antonio and Scenic Loop Substation, west of IH 10 near Boerne. Both projects included public open houses with respective area residents.  

New substations increase reliability of electric service by moving the electricity through additional distribution circuits to meet the increased need for power in area where it is needed. It reduces the likelihood of extended power outages and helps us restore power faster.

Substations also provide an additional source of electricity allowing us to reroute power more quickly. Think of it as a detour on our city streets. When there is construction, traffic is rerouted to ensure drivers can reach their destination. In the electric distribution world, a fault or cause of the outage is the “construction” and our substations help detour the power from the other side of the fault to bring electric service back on more quickly to those customers. Without the substation, everyone affected would be without power until the fault is cleared or fixed. Our distribution system is set up in such a way that miles of overhead electric lines are exposed to elements such as wind, trees, lightning, animals and even vehicle accidents with our utility poles. All of these can contribute to power outages. Supplying power from nearby substations can drastically reduce the amount of time customers are without power.

Finding the right site for constructing a substation is not always easy, but it’s a necessary part of how we provide reliable and resilient service. Conducting open houses and meeting face-to-face with our customers is a step we embrace. It not only gives us an opportunity to answer questions, but it also allows us to receive feedback and listen to our community’s concerns. It’s a process we will continue to explore as demand for electricity grows.

If you’re interested in learning more about our current substation project in the Midtown San Antonio area near San Pedro and Hildebrand, join us at a Board Public Input Session on Feb. 4, 2020, from 5:30 p.m. to 7:30 p.m. at Temple Beth-El, 211 Belknap Place.

Here are some frequently asked questions:

What is the difference between a transmission and distribution line?

Typically, electricity is generated from remotely located electric power plants (including wind and solar farms) and then travels from those remote generating sources to substations closer to population centers through a system of high-voltage transmission lines. Once at a substation, the electricity is reduced to a voltage level that is appropriate for distribution to customers. Electricity then travels from the substation through the network of distribution lines, supplying electricity to homes and businesses.

Can infrastructure be placed underground?

Distribution lines can be placed overhead and underground.  Distribution lines typically exit the substation underground and connect to overhead poles outside the substation. CPS Energy’s standard is to install distribution lines above ground outside the substation due to the significant difference in cost.  Underground infrastructure is placed in areas where overhead infrastructure is not feasible. 

Do substations make a lot of noise?

Within our distribution substations, the equipment is near silent.  The main producers of sound are the power transformers that convert voltage levels.  Because most of the transformers we install to serve our customers are located within populated areas of San Antonio, we’re mindful to include transformer noise limitations within our specifications that the manufacturer must adhere to.  The result is a better use of transformer materials and manufacturing processes that create less vibration sound from our substation transformers.  Sound levels at the power transformers are 70-75dBA and normally closer to the 70dBA mark.  The sound lessens before it travels beyond the substation perimeter and is normally not discernible from ambient noise levels beyond that.

Is there a lot of lighting around substations?

Substation lighting is an essential component of personnel safety, substation security, and electric reliability.  While lighting is necessary, the amount of lighting installed can be influenced to some degree by the geography of the substation location and the population in the immediate area.  With these things in mind, various types of lighting have been employed over the years to be mindful of the community while maintaining suitable levels of lighting needed within the substations.  Most recently, we’ve been looking toward LED lighting technology with various modes of lighting.  This is still being explored, but the desire is to have a lighting system that allows for situational levels of lighting that would increase for detected motion or to support restoration efforts taking place in the substation and return to a more subdued normal level otherwise.

Do substations increase traffic flow from employees working there?

Not necessarily. Traffic typically does not increase in the area of new substations. Once the substation is completed, it is likely CPS Energy crews will only need to access the station 2-3 times a year for maintenance, unless there is an emergency.

John Moreno

John is part of the Corporate Communications team at CPS Energy.

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