Typical operating and maintenance (O&M) costs for pumped hydro storage (PHS) plants include labor, routine maintenance, repairs, and periodic overhauls primarily related to pumps, turbines, and associated equipment.
Breakdown of O&M Costs for Pumped Hydro Storage Plants
- Labor Costs:
A typical PHS plant requires continuous staffing for 24/7 operation. For example, a facility might employ about 25 operators to cover shifts around the clock, which is a significant portion of fixed O&M costs. - Routine Maintenance and Repairs:
Variable O&M costs include parts replacement and repairs of electromechanical equipment such as pumps and turbines. Parts costs are estimated at about 40% of labor costs and are generally calculated on a $/kW basis. Repairs are projected every five years, costing approximately 1% of the electromechanical equipment cost. - Overhaul Costs:
Major overhauls are expected roughly every 10 years. For instance, overhauls may cost about $16/kW-year or around $40 million for a 250 MW unit. These costs are substantial but are not strongly dependent on plant size. - Other Maintenance Activities:
Additional maintenance includes HVAC system servicing, smoke and heat rejection system upkeep, outdoor maintenance of dams and roads, and supervisory staff expenses. For example, outdoor maintenance may constitute about 15% of O&M efforts, electronics repair 3%, rotary equipment repair 3%, HVAC and related systems 3%, and supervisors 8%.
Overall Cost Perspective
While exact dollar amounts vary by plant size, design, and location, O&M costs tend to be a smaller fraction of total lifecycle costs compared to capital expenditures. For larger facilities (e.g., 1,000 MW), labor costs per unit capacity are lower due to economies of scale. This means that bigger plants benefit from relatively lower O&M costs per megawatt than smaller installations.
Summary Table
| O&M Cost Component | Typical Cost Estimate | Notes |
|---|---|---|
| Labor | Covers 24/7 operation, ~25 operators | Fixed O&M, significant but stable |
| Parts Replacement | ~40% of labor costs, calculated $/kW | Variable O&M |
| Repairs | About 1% of electromechanical cost every 5 years | Includes pump/turbine repairs |
| Overhauls | $16/kW-year or ~$40M per 250 MW unit every 10 years | Major scheduled overhaul expense |
| Other Maintenance | ~15% dams/roads, ~3% electronics, HVAC, rotary repairs, 8% supervisors | Routine facility upkeep |
In essence, the O&M expenses for pumped hydro storage plants are dominated by labor for continuous operation and scheduled maintenance and repairs on mechanical and electrical components. These costs tend to be moderate relative to the initial capital investment but are critical for the reliable long-term operation of the plant.
No specific dollar per kWh O&M cost figures were detailed explicitly in the provided sources, but the components above define the typical structure and scale for these expenses.
This summary is drawn primarily from detailed cost assessments and operational models such as those reported by the U.S. Department of Energy and related studies.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-typical-operating-and-maintenance-costs-associated-with-pumped-hydro-storage-plants/
