Rettew Associates, Inc.

RETTEW Associates, Inc., headquartered in Lancaster, Pennsylvania—with additional offices such as Williamsport—has established itself as an innovative leader in engineering consulting for renewable energy solutions since its founding in 1969. The company specializes in delivering vertically integrated EPC services for commercial/industrial solar installations, utility-scale solar farms, floating solar arrays (including some of North America’s largest), and battery energy storage systems. RETTEW’s expertise spans from initial project strategy through design engineering to construction management and operational support.
Their team is recognized for successfully navigating complex regulatory environments while providing cost-effective solutions that reduce clients’ carbon footprints. Notable achievements include designing one of Pennsylvania's larger ground-based solar arrays—a 2.7 MW system powering a significant portion of a water authority's needs—and developing one of the largest floating solar arrays in the United States at Sayreville’s water treatment plant. Their approach emphasizes sustainability by integrating alternative energy sources like biogas alongside traditional renewables.
Beyond technical excellence, RETTEW is committed to community engagement—participating actively in local mentoring programs—and maintains a reputation for reliability among both private sector clients and public utilities seeking resilient infrastructure upgrades.