To understand this issue, it is important to distinguish between traditional power plants and modern renewable sources. Traditional power plants, such as nuclear facilities, use massive spinning turbines. These turbines provide inherent physical inertia, which acts like a shock absorber for the electrical grid. If there is a sudden change in demand or supply, this physical momentum helps keep the grid frequency stable.
In contrast, most renewable energy sources like solar panels and wind turbines connect to the grid via power electronics called inverters. These inverters do not provide natural mechanical inertia. As we replace traditional spinning generators with these inverter-based resources, the overall physical inertia of the power grid decreases. This makes the grid frequency much more sensitive to sudden fluctuations.
When grid frequency drops too quickly due to low inertia, it can trigger protective systems in nuclear power plants. These safety mechanisms are designed to automatically disconnect the plant from the grid to prevent damage to the reactor. If multiple plants trip simultaneously due to frequency instability, it can lead to a cascading failure and widespread blackouts. Maintaining grid stability during this energy transition requires advanced technology to simulate inertia electronically.
