Measures to minimize water loss due to evaporation in pumped hydro storage (PHS) systems focus primarily on reducing the exposed surface area of water and controlling environmental conditions around the reservoirs. Key strategies include:
1. Use of Floating Solar Panels
- Installing floating solar photovoltaic (PV) panels on the surface of pumped hydro reservoirs can significantly reduce evaporation by shading the water from direct sunlight. This also allows dual use of the water surface for solar energy generation and evaporation control, improving overall efficiency.
2. Optimizing Reservoir Location and Design
- Building upper reservoirs at higher elevations can help because temperatures tend to be cooler at altitude, reducing evaporation rates. For example, a reservoir positioned about 500 meters (a third of a mile) above the lower reservoir experiences air temperatures about 3.2°C cooler, which helps lower evaporation.
- Designing reservoirs to minimize surface area relative to volume can reduce evaporative losses since evaporation depends on water surface exposure.
3. Operational Timing
- Pumping water uphill primarily at night when temperatures are lower and releasing it during the day can help keep water in the cooler upper reservoir during the hotter daytime periods, thus reducing evaporation.
4. Use of Physical Covers and Barriers
- Though less common at large scale, physical barriers such as floating covers or specialized evaporation retardants could be applied to reservoir surfaces to reduce water loss.
5. Make-up Water Management
- While not a prevention method, maintaining minimal operational make-up water to offset inevitable evaporation losses is necessary to sustain reservoir levels in long term operation.
Summary Table of Measures
| Measure | Description | Effectiveness |
|---|---|---|
| Floating solar panels | Shade water surface and generate electricity | High (dual benefit) |
| High elevation reservoirs | Utilize cooler air at altitude to reduce evaporation | Moderate to high |
| Operational timing | Pump water at night, store in cooler upper reservoir | Moderate |
| Physical covers/barriers | Floating covers or retardants to block evaporation | Variable, depends on implementation |
| Make-up water supply | Regular replenishment to offset evaporation | Necessary but not preventative |
These combined measures can substantially reduce water loss due to evaporation in pumped hydro storage systems, enhancing water conservation and system efficiency.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-measures-can-be-taken-to-minimize-water-loss-due-to-evaporation-in-pumped-hydro-storage-systems/
