A solar farm in Texas need to replace damaged collector lines running from the thousands of solar panels on the property.
But first, they needed to locate those lines.
GPRS Project Managers Scott Moore and Miguel Campos, and Area Manager Keith Knoblock were called out to the roughly 1,200-acre property in East Bernard, Texas, where local wildlife had been digging up and gnawing on the lines which collect and transport electricity from solar cells.
“Whoever did the installation work wasn’t the company that we were contracted with,” Moore explained. “When they buried the lines, they did a great job keeping everything in order, everything in line, but they didn’t put anything in conduit. These lines are about the size of like a cable TV line, and so what happened is the wildlife in that environment would like to have dinner via those lines, so they were shorting out and burning up a lot of these combiner boxes and fun stuff like that.”
The GPRS team used electromagnetic (EM) locators to find the damaged collector lines.
Unlike ground penetrating radar (GPR), which utilizes radio waves to detect buried utilities and other subsurface obstructions, EM locators detect the electromagnetic signals radiating from metallic pipes and cables.
EM locators can operate in both active and passive mode.
Active Location Mode is used to trace, identify, and pinpoint a buried line. It also can be used to measure the depth estimation of the buried line, or the signal current on that line.
Passive sweeps are used to mark the location of unidentified, buried lines prior to breaking ground. Passive signals can originate from a variety of sources:
Power
- Current flowing through a live electrical wire
- Cathodic protection for pipelines
- Stray currents from power transmission systems can use any conductive pipe as a return path
Note: Finding a power reading does not necessarily mean that an electrical line has been located. The line should be identified by tracing it to its source or an electrical structure.
Radio
- Any conductive pipe or utility can act as an antenna for radio wave transmissions in the atmosphere and enter the ground
- Some active phone lines
- Stray currents from power transmission systems can use any conductive pipe as a return path
Note: Radio Mode cannot calculate depth readings. Once a radio reading has been found, induction could be used to assist with tracing and depths.
Rebar
- Reinforcing such as rebar and mesh will often re-radiate these signals and can provide false positive readings
- Raising the receiver and adjusting the gain to eliminate the weaker readings from the rebar may allow the stronger reading from the utility to be traced
- After adjusting the height, a GPRS Project Manager will continue sweeping and tracing at that height
Because of the damage to the collector lines, Moore and his fellow GPRS team members needed to locate them with passive sweeps.
“Since a lot of these lines were melted, chewed through, things like that, really you couldn’t actively locate them,” he explained. “So, we were basically locating these lines with our passive methods, which turned out to be just the quickest way to handle this job.”
The solar farm operator wanted to move fast to repair the damaged lines and ensure their operation was working at full capacity. Throughout the project, their repair crews were often working right behind GPRS; no sooner would we locate the lines then they would excavate and replace them with new lines encased in protective conduit.
But thanks to the efficiency of GPRS’ SIM-certified utility locating process, our team ended up outpacing the repair crew.
“We got to where we were weeks ahead of their rate of pace, which they were happy with,” Moore said.
In addition to marking the location of the collector lines with spray paint and flags, Moore and his team members uploaded all the data they collected into SiteMap® (patent pending), GPRS’ project & facility management application that provides accurate existing conditions documentation to protect assets and people.
SiteMap® is a single source of truth for the critical infrastructure data needed to eliminate the costly and potentially dangerous mistakes caused by miscommunications. Securely accessible 24/7 from any computer, tablet, or smartphone, SiteMap® allows you and your project team to plan, design, manage, dig, and ultimately build better.
With SiteMap®, the solar farm operators will have accurate data on the connector lines pulling electricity from the hundreds of solar panels on their property, which will help ensure the safety of any future maintenance projects.
From skyscrapers to sewer lines, GPRS Intelligently Visualizes The Built World® to keep your projects on time, on budget, and safe.
What can we help you visualize?
Frequently Asked Questions
What type of informational output is provided when I hire GPRS to conduct a utility locate?
Our Project Managers flag and paint our findings directly on the surface. This method of communication is the most accurate form of marking when excavation is expected to commence within a few days of service.
GPRS also uses a global positioning system (GPS) to collect data points of findings. We use this data to generate a plan, KMZ file, satellite overlay, or CAD file to permanently preserve results for future use. And all this data is uploaded into SiteMap® for your 24/7, secure access.
GPRS does not provide land surveying services. If you need land surveying services, please contact a professional land surveyor. Please contact us to discuss the pricing and marking options your project may require.
Will I need to mark out the utilities that GPRS locates?
GPRS will locate and mark all utilities for you. We have a variety of tools and markers we can use to highlight the locations of utilities, underground storage tanks (USTs) and whatever else may be buried on your site.
