Caterpillar Inc. introduced two G3520C natural gas generator sets with optional air and fuel system controls that have been enhanced to provide superior island mode operational capability. Designed for commercial and institutional customers that require exceptionally reliable, high-quality electric power, the island mode control system option for the G3520C gas generator sets, offered in 60 Hz and 50 Hz versions, allows customers to generate power independently from the power grid with a high-efficiency, natural gas-fueled engine. Driven by an electronically controlled, lean-burn gaseous-fueled reciprocating Cat engine, the G3520C generator set was designed to offer a high power density and excellent fuel efficiency while maintaining tight NOx control.