The availability of water resources is a significant factor influencing the location of pumped hydro storage (PHS) facilities, but it is not the only or necessarily the primary constraint.
Water Resource Requirements and Impacts
- Water Use and Recycling: Pumped hydro storage relies on two reservoirs at different elevations. Water is pumped from the lower reservoir to the upper reservoir during low electricity demand and released back down through turbines to generate electricity during high demand. The system primarily recycles the same water between reservoirs for decades, so the initial water fill is the main water use, about 1 gigalitre per gigawatt-hour of storage capacity. After that, only losses from evaporation or seepage need to be compensated, often by local rainfall or minor inflows.
- Closed-Loop Systems: Many potential PHS sites are designed as closed-loop systems that are not connected to rivers or major waterways. These off-river systems reduce environmental impact and water dependency, as they do not rely on continuous river flow or large natural water bodies.
Geographic and Environmental Considerations
- Elevation Difference and Topography: The main geographic requirement is hilly or mountainous terrain to provide sufficient elevation differential between reservoirs. This natural elevation difference is critical for storing gravitational potential energy efficiently.
- Water Availability: While water availability matters, regions with regular rainfall are preferred to maintain reservoir levels and compensate for evaporation losses. Dry regions are less desirable unless water can be sourced sustainably.
- Environmental and Land Impact: PHS facilities generally require less land and water compared to many renewable energy installations and have minimal carbon emissions, especially when using closed-loop designs. Being able to site away from rivers and natural ecosystems also reduces environmental concerns related to water use.
Summary
| Aspect | Influence of Water Availability |
|---|---|
| Initial Water Fill | Requires about 1 gigalitre per GWh of storage |
| Ongoing Water Use | Minimal; mainly to compensate evaporation and seepage |
| Preferred Climate | Areas with regular rainfall to replenish reservoirs |
| System Type | Closed-loop (off-river) preferred to reduce water reliance |
| Location Terrain | Hilly/mountainous terrain needed for elevation difference |
| Environmental Impact | Low water footprint if designed properly |
In essence, the availability of water resources influences PHS location primarily through the need for an initial water fill and the ongoing replacement of losses. However, PHS facilities often utilize closed-loop designs in hilly areas with sufficient rainfall, making water availability less restrictive than for other forms of hydropower. This flexibility greatly expands the potential locations for pumped hydro storage beyond sites with large natural rivers or reservoirs.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-availability-of-water-resources-influence-the-location-of-pumped-hydro-storage-facilities/
