Abstract: Embodiments of an engine generator set are provided herein with a compact, modular design and improved cooling characteristics. The engine generator set embodiments may generally comprise a horizontally shafted engine and alternator, and a cooling system. In some embodiments, the embodiments may include a set of on-board transformers. The cooling system includes one or more components, such as a radiator and one or more electrically driven fans, which are mounted above and/or below the horizontally shafted engine and alternator in a vertical stack. A generator set housing encloses the horizontally shafted engine and alternator, the cooling system and the set of on-board transformers (if included), as well as other generator set components. Due in part to the vertical stacking of the cooling system components, a height of the generator set housing may be substantially larger than a length of the generator set housing, resulting in a substantially reduced footprint, as compared to conventional generator sets.