For decades, Peru’s coastal power grids have faced a persistent and costly enemy: the salty, humid air that sweeps in from the Pacific Ocean. Along the country’s arid southern coastline—home to major cities like Lima, Callao, and Trujillo—salt particles carried by onshore winds (known locally as "la brisa salada") settle on transmission line insulators, creating a conductive film when mixed with moisture from morning fog or occasional rain. This film causes pollution-induced flashovers—sudden, dangerous voltage leaks that can shut down entire sections of the grid, disrupt industrial operations, and leave thousands of households without electricity. For Red de Energía del Perú (REP), the country’s largest power transmission company, the problem was particularly acute on its 500kV Fénix-Chilca line—a critical 7.5-kilometer corridor connecting the 580MW Fénix substation (powered by natural gas and hydroelectric plants) to Lima’s urban grid, which serves over 10 million people.

Before 2020, REP relied on polymeric (plastic-based) insulators for the Fénix-Chilca line, but these proved ill-suited to the coastal environment. "Polymeric insulators are lightweight and cheap, but their surface degrades quickly in salty air," explains Carlos Mendez, REP’s Chief Technical Officer. "The plastic would become brittle, crack, and lose its insulating properties after just 3-4 years. We were cleaning the insulators every 12 months—using high-pressure water trucks that had to block traffic on the nearby Pan-American Highway—and replacing 15-20% of the units annually. The maintenance costs added up to $1.2 million per year, not to mention the penalties we paid to utility companies when flashovers caused blackouts."

In 2020, REP made a pivotal decision: to replace all 1,200 polymeric insulators on the Fénix-Chilca line with RTV-coated glass insulators. RTV, or room-temperature vulcanizing silicone, is a flexible, durable material that forms a protective layer over the glass surface. When combined with glass’s inherent advantages, this coating creates an insulator that can withstand even the harshest coastal conditions.

Glass itself is naturally resistant to the challenges of coastal environments. Unlike polymeric materials, it has low thermal expansion—meaning it doesn’t expand or contract significantly with temperature swings (which can range from 15°C at night to 35°C during the day in coastal Peru), preventing cracks and leaks. Its chemical stability also makes it impervious to corrosion from saltwater or acidic pollutants, ensuring it retains its insulating properties for decades. The RTV coating enhances these benefits by adding superior hydrophobicity—the ability to repel water. Water droplets bead up and roll off the RTV surface, rather than spreading into a conductive film, and the coating also prevents salt particles from adhering tightly to the glass. Tests by REP’s engineering team showed that the RTV-coated glass insulators had a water contact angle of over 110° (compared to 70-80° for uncoated glass and 60-70° for polymeric insulators)—a key measure of hydrophobicity, with higher angles indicating better water repellency.

Four years after the upgrade, the results have been transformative. REP’s maintenance records show that the RTV-coated glass insulators have required only one cleaning (in 2022, after an unusually heavy dust storm) and zero replacements. Flashovers on the Fénix-Chilca line have dropped from an average of 8-10 per year to zero—saving REP over $900,000 in annual maintenance costs and eliminating blackout-related penalties. "We’ve gone from worrying about this line breaking down every few months to barely thinking about it," Mendez says. "It’s been a game-changer for our operations."

The success of the Fénix-Chilca project has sparked interest across Peru and beyond. REP is now planning to upgrade 12 more coastal transmission lines with RTV-coated glass insulators by 2026, and similar projects are underway in other salt-prone regions: Chile’s Atacama Desert (home to large solar farms), Australia’s Western Australian coastline, and even coastal areas of the United States, like Florida and Texas.

Glass insulators are also proving effective in other extreme environments, from the freezing temperatures of Canada’s northern grids (where ice buildup is a major threat) to the polluted industrial zones of India’s Punjab region (where smoke and dust cause frequent flashovers). "What makes glass insulators unique is their versatility," says Dr. Ana Lopez, a researcher at the IEEE Power & Energy Society, who recently published a study on insulator performance in extreme conditions. "In our tests, RTV-coated glass insulators outperformed both porcelain and polymeric alternatives in anti-pollution flashover tests—withstand voltages 25% higher than porcelain and 40% higher than polymers. They balance performance, durability, and cost in a way that no other insulator material can."

As the world’s power grids face growing pressure to adapt to climate change—from more frequent storms and heatwaves to rising sea levels—innovations like RTV-coated glass insulators are becoming essential tools for ensuring energy security. For coastal communities like those in Peru, they’re not just technical upgrades—they’re a promise of more reliable electricity, fewer blackouts, and a more resilient energy future.