ARE Project Management (PjM) Practice Exam

Which generation unit should be restored first in a restoration procedure?

1. Pumped hydro unit with plenty of water

2. Small CT that is electrically distant

3. Nuclear unit that was on-line prior to disturbance

4. Coal-fired steam unit that was on-line

The correct answer is: Pumped hydro unit with plenty of water

In a restoration procedure following a disturbance, the primary goal is to restore power reliably and efficiently. The best choice for the first generation unit to be restored is a pumped hydro unit with plenty of water. Pumped hydroelectric storage is highly effective for ramping up or down quickly, due to its ability to generate electricity on demand. When water is abundant, the efficiency and responsiveness of this unit allow it to stabilize the grid by providing immediate power while other slower-to-respond units are brought online. Pumped hydro units can quickly adjust their output to meet changes in demand, making them ideal for the initial phases of restoration. Their operational flexibility and availability of stored energy can help manage frequency and voltage levels effectively while additional power-generating resources are brought back online. The other generation units, while vital to the overall power restoration process, may not have the same rapid response capability. For instance, nuclear units typically take longer to come back online due to safety protocols and the need for systems to achieve stable conditions. Coal-fired steam units also require significant time to reach operational levels, and a small combustion turbine that is electrically distant might not contribute to the immediate restoration needs in an efficient way compared to a pumped hydro unit that is readily available and responsive.