With 20+ years of experience and over 10,000 solar PV projects to date, equating to 850MW, Castillo Engineering is one of the ... most experienced solar PV engineering firms in the United States. The firm delivers expertise in full service (Array, Electrical, Structural, Civil) solar PV design, engineering and consulting services for projects ranging from residential, industrial, commercial and utility-scale. From 7kW to 70MW, We Design to Permit®. read more