A standby generator includes a standby housing defining a cavity and an internal combustion engine. The engine includes an engine block including a cylinder comprising a piston, an engine housing at least partially covering the engine block, and a crankshaft configured to rotate about a vertical crankshaft axis in response to movement by the piston. The standby generator also includes an alternator configured to generate alternating current electrical power, a controller comprising a rectifier configured to convert the alternating current to a direct current and an inverter configured to convert the direct current to a clean alternating current electrical power, and a transfer switch configured to receive the clean alternating current electrical power from the controller and at least one of grid, solar, or battery power, and configured to supply power to an electrical load. The internal combustion engine, the alternator, and the controller are positioned within the cavity.