Sandia and Guardian Sensors Inc. have developed electrical in-line connectors that automatically predict and prevent solar panels from catching fire.
High-power discharges of electricity can create explosions or flash events in photovoltaics due to damaged wires. There is thus an urgent need for panels to have built-in capabilities to extinguish fires caused by arc-faults.
Sandia scientist Kenny Armijo has spent 10 years working alongside other researchers at the labs and local company Guardian Sensors Inc. to understand and characterize these hazardous arc-faults.
Their work has now led to the development of electrical in-line connectors that automatically predict and prevent photovoltaic arc-faults before they can ignite electrical fires.
The in-line connector developed by Guardian Sensors consists of a metal spring covered in a special type of self-extinguishing polymer material developed and tested at Sandia over the last five years.
Like current connectors, the self-extinguishing mechanisms would link a series of solar panels like a string of Christmas lights that could operate together in a field or on a roof.
All connectors are susceptible to corrosion, damage or improper installation, which can lead to reliability issues, especially if there are tiny crevasses or breaks in the wires.
Currently, when this happens, sparks and devastating fires can occur when high current and voltage run through damaged connectors.
Till date, there hasn’t been a completely reliable way for the connectors themselves to prevent the danger – but that is all about to change thanks to the Sandia-Guardian Sensors collaboration.
The new in-line connectors have been built to activate at temperatures above 185 degrees Fahrenheit. When that happens, the special self-extinguishing material melts, fills in the crevasses or breaks in the wires and extends the spring which increases the spark gap between wire conductors, so they can no longer produce energy that leads to heat and fires.
A combination of the speed of the reaction and the material’s fire-resistant properties will stop a fire before it starts – all in less than 2 seconds, says Armijo.
The self-extinguishing materials used in the connectors were developed from Sandia-based research and Guardian Sensors was given access to a patented, special arc-fault generator located at the labs.
Going forward, Armijo is hoping to expand this research to other types of power sources and storage devices, like batteries for instance.
Image and content: Kenny Armijo/Sandia