Multiple turbines can drive a single generator for efficiency and cost-effectiveness, as having a single generator reduces internal losses from resistance and friction. Common configurations include steam turbines with high, intermediate, and low-pressure stages acting on the same shaft, or gas turbines in series within combined cycle power plants. While cross compound turbines with multiple shafts and generators exist, they are less common today. The discussion highlights the importance of understanding turbine types and configurations in power generation systems. Overall, utilizing multiple turbines on one shaft is a practical approach in energy production.