Facilitating Large-Scale Snow Shedding from In-Field Solar Arrays using Icephobic Surfaces with Low-Interfacial Toughness

Abstract

Large-scale accrual of snow and ice on solar arrays in northern latitudes can cause significant power generation losses during winter. Depending on environmental conditions, snow can encompass a wide range in physical characteristics from dry snow (modulus ≈100 kPa and density ≈0.1 g cm−3) to bulk ice (modulus ≈8 GPa and density ≈0.9 g cm−3). This variation in snow morphology has made the development of a passive, broad-spectrum, snow and ice-shedding surface challenging. Here, the authors develop one of the first surfaces that simultaneously possesses both low-interfacial strength (τ˄ice < 50 kPa) and toughness (Γice < 0.5 J m−2) with ice. These surfaces, fabricated via the addition of mobile polymer chains/oils to a thin polymeric coating, require extremely low detachment forces for ice, enabling its passive shedding at virtually any accretion length scale. Preliminary evidence that the new surfaces can shed different forms of snow and ice from field-deployed solar arrays, over a range of subzero temperatures for several weeks, leading to significant increases in power generation is provided. The optically transparent surfaces are easily scalable and can be widely deployed by the solar industry in areas that see persistent snow. Other applications include automotive windshields, LIDAR covers for autonomous vehicles, and cold climate optical sensors.Coatings that simultaneously possess both low-interfacial strength and toughness with ice are developed. These surfaces can shed different forms of snow and ice from field-deployed solar arrays, over a range of subzero temperatures for several weeks, leading to significant increases in power generation.