A hybrid power generation system and method for marine vessels, such as tug boats, is disclosed. The system integrates multiple diesel generators and battery energy storage with advanced control via a Load Sharing Processor executing a computer program stored in a non-transitory computer-readable medium. The control program utilizes linear programming, neural networks, or expert systems to dynamically manage load distribution and optimize fuel efficiency based on real-time operating states of the diesel engines and batteries. The system ensures reduced emissions, improved power response to transient loads, and prolonged engine life by minimizing unnecessary diesel generator operation. The method includes managing system load, calculating optimal operating states, and adjusting power sources accordingly, including temporary battery-driven peak shaving and dynamic generator activation and deactivation.