Containerized ultra-low nox diesel engine generator set with roof-mounted selective catalytic reduction system

A containerized generator set with roof‑mounted SCR subsystem, comprising:

• an enclosure comprising a roof and defining an interior housing an engine and an electrical generator;
• and
• a selective catalytic reduction (SCR) subsystem mounted on the roof of the enclosure, the SCR subsystem comprising:
• an exhaust gas inlet aligned with an engine exhaust exit of the engine, the exhaust gas inlet configured to receive the exhaust gas from the engine, wherein the exhaust gas comprises a first concentration of nitrogen oxides;
• a mixer configured to receive a reductant and to mix the reductant with the exhaust gas;
• an SCR unit comprising a catalyst and configured to reduce NOx in the exhaust gas to a second concentration of nitrogen oxides, wherein the second concentration of nitrogen oxides is lower than the first concentration of nitrogen oxides;
• an exhaust silencer configured to reduce noise emitted from the containerized generator set;
• and
• an exhaust gas outlet configured to discharge treated exhaust gases to atmosphere;
• wherein the SCR subsystem is arranged along the roof of the enclosure, wherein the arrangement routes the exhaust gas from the engine upwardly from the interior of the enclosure to the roof‑mounted SCR subsystem.