Overview of Open-Loop and Closed-Loop Systems
- Open-Loop Systems: These typically utilize existing natural water bodies (such as rivers and lakes) to create the upper and lower reservoirs. The water intake and discharge are directly connected to these water bodies, which can be influenced by environmental factors like river flow and quality.
- Closed-Loop Systems: These require two entirely new, constructed reservoirs. They are isolated from natural water bodies, which can reduce environmental impacts but usually increase construction costs due to the need for creating both reservoirs.
Cost Considerations
- Capital Costs: Closed-loop systems generally have higher initial capital costs because they require the construction of both reservoirs, whereas open-loop systems often use existing natural bodies of water, reducing construction expenses for the reservoirs themselves.
- Environmental Costs and Impacts: Open-loop systems can have significant environmental impacts due to water withdrawal and discharge into natural bodies, potentially affecting aquatic life. Closed-loop systems mitigate these risks but at a higher upfront cost.
- Levelized Cost of Storage (LCOS): The LCOS for pumped hydro, including both open and closed-loop systems, falls within a similar range of approximately $70 to $170 per megawatt-hour. This suggests that while closed-loop systems may have higher capital costs, their overall storage costs can be comparable when considering environmental benefits and operational simplicity.
Conclusion
Closed-loop pumped hydro projects typically have higher initial capital costs due to the construction of two new reservoirs, but they offer reduced environmental impacts compared to open-loop systems. The LCOS remains similar for both types, indicating that operational efficiency and environmental advantages can offset higher construction costs in the long term.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-cost-differences-between-open-loop-and-closed-loop-pumped-hydro-projects/
