Utilities in Brazil and other fast-growing transmission markets are balancing rising demand, constrained rights-of-way, and the need to strengthen infrastructure against severe weather. These pressures are pushing transmission planners to look beyond conventional structure designs and consider approaches that can increase capacity, improve resilience, and make better use of existing corridors.
One emerging approach is the molded-insulator crossarm assembly (MICA), a design that integrates insulation and structural support into a single crossarm system. By rethinking how transmission structures manage electrical and mechanical performance, MICA offers a practical path for compact line design, uprating projects, and grid modernization.
At a glance, MICA is designed to help utilities:
Unlike traditional steel crossarms, MICA uses composite insulators as both electrical insulation and structural support. By combining multiple insulators into a unified assembly, MICA can carry the same multi-axis loads as conventional tower components while maintaining high electrical performance.
This advancement addresses key limitations of earlier insulated crossarm approaches, which struggled with longitudinal load capacity and were typically limited to lower voltage applications.
MICA enables two critical advantages for utilities:
Together, these capabilities allow utilities to expand system performance without acquiring new rights-of-way, making MICA a powerful tool for modern grid constraints.
A recent Hubbell-led project demonstrated a 230-kV MICA solution designed to meet both structural and electrical requirements in real-world conditions.
Full-scale testing confirmed performance across key criteria, including:
Because MICA combines multiple insulators into a single structural system, geometry plays a critical role in performance. Advanced modeling helps optimize electric field distribution and minimize stress points across the assembly.
This design approach ensures reliable operation not only in new builds but also in retrofit and uprating applications where existing tower configurations must be considered.
MICA represents a shift toward integrated, multifunctional infrastructure that delivers mechanical strength, electrical performance, and space efficiency in a single solution.
As industry standards evolve and adoption grows, insulated crossarm systems like MICA are quickly moving from innovation to implementation, helping utilities build more resilient, efficient, and adaptable transmission networks.
Download Hubbell's technical paper on engineering and testing its MICA design.