Using disused mines as reservoirs for pumped hydro storage (PHS) offers notable environmental benefits but also presents some specific risks that must be managed carefully.
Environmental Benefits
- Reduced Ecological Footprint: Unlike traditional PHS projects that require constructing large reservoirs by flooding natural valleys or damming rivers, using abandoned mines leverages existing excavated cavities. This avoids extensive earthworks, significant habitat destruction, or ecosystem modification often associated with new reservoir construction.
- Minimal Landscape Disruption: Many former mines already have extensive subsurface spaces suitable for water storage, which means that underground reservoirs can be created without further disrupting the landscape or displacing nearby communities.
- Use of Previously Disturbed Land: Since mines are brownfield sites where land was already cleared and industrialized, repurposing them for hydro storage avoids clearing new vegetation or impacting areas of cultural, social, or environmental significance. Additionally, mining sites often have existing infrastructure such as roads, water access, and electrical transmission lines, which facilitate project development with lower new environmental disturbance.
Potential Environmental Risks
- Water Quality and Heavy Metal Pollution: One significant concern is the potential for pollution from residual contaminants left in abandoned mines. Studies have shown that reservoirs formed in underground goaf (collapsed mine areas) can release heavy metals into the water. Such contamination risks threatening water quality, potentially impacting downstream surface waters and aquatic ecosystems if not properly managed.
- Need for Water Purification and Monitoring: The presence of mine pollutants may necessitate treatment or purification technologies for the reservoir water to ensure normal operation and to preserve the longevity of the hydro storage equipment.
- Site-Specific Geographical Constraints: Suitable mine sites must meet geographical criteria, such as having sufficient height differences and water availability for pumped storage. This restricts potential locations and may require additional reservoirs outside the original mine area, which could involve additional environmental considerations.
Summary
| Aspect | Environmental Impact | Notes |
|---|---|---|
| Land Use | Minimal new land disturbance | Uses already excavated mine cavities |
| Habitat & Ecosystems | Low impact | Avoids flooding natural valleys or rivers |
| Infrastructure | Existing mining infrastructure usable | Reduces need for new roads or power lines |
| Water Quality | Risk of heavy metal pollution | Requires monitoring and possibly water treatment |
| Community Displacement | None | Mines usually remote, no new displacement |
| Cultural/Social Impact | Reduced risk | Mines less likely to be culturally sensitive |
In conclusion, converting disused mines to pumped hydro storage reservoirs generally lowers environmental impacts compared to new reservoir construction, particularly in terms of land disturbance and habitat loss. However, careful assessment and management of water quality risks, especially heavy metal contamination, are critical to ensure environmental safety and sustainable operation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-environmental-impacts-of-using-disused-mines-as-reservoirs-for-pumped-hydro-storage/
