In combined operation of several power plants the reserve capacity requirement is reduced.

The combined operation of several power plants within a power system notably reduces the reserve capacity requirement compared to operating each plant in isolation. This reduction is primarily due to the diversification of risk and the sharing of reserve capacity among the plants. Here’s why and how this happens:

1. Diversification of Risk: In a standalone power plant operation, the entire load must be managed by that single plant, including any peak demands or unexpected increases in load. Consequently, the plant must maintain a high level of reserve capacity to handle these situations. However, when multiple power plants operate in a combined manner, the risk of a sudden increase in demand or unexpected outage is spread across all plants in the system. This means that not every plant has to be prepared for the worst-case scenario independently.

2. Pooling of Reserve Capacity: In a combined system, the reserve capacity can be pooled. This means that the total system reserve can be less than the sum of the individual reserves that each plant would have needed if it were operating alone. The probability that all plants will face their peak demand or a failure at the same time is low, so the system can rely on a smaller total reserve margin.

3. Increased System Flexibility: The combined operation often includes a diverse mix of power plants, such as base-load plants (often nuclear or coal-fired), load-following plants (such as natural gas plants), and peaking units (like gas turbines or hydroelectric plants with reservoirs). This diversity allows