3 ms·
I assume evaporation is gonna be below an inch a day in even the most hot and dry climates. Considering the total height of the water column it's negligible.
by ema 8y ago
I assume evaporation is gonna be below an inch a day in even the most hot and dry climates. Considering the total height of the water column it's negligible.
- allannienhuis 8y agoI'm not disagreeing, but wouldn't you need to compare the total volume lost to evaporation to the total volume of water pumped (== cost) to have a sense for whether it's a significant factor? Its hard to build up a casual sense for how much water is lost to evaporation in most lakes we have experience with because the lake's level is based on geography (level of the outlet) when there's a source of water coming in to replenish it. It could be a larger factor than we think. That said, I expect that the efficiency losses in the pumping and generation steps would dwarf evaporation. Any storage system has some losses; the ability to store larger volumes makes up for efficiency disadvantages compared to things like batteries might have.
- seanalltogether 8y agoI wonder if evaporation is offset entirely by water that naturally flows into the reservoir. The graphic on the page seems to indicate that there is always a small amount of water flowing down through the system regardless of whether any uphill pumping occurs, which would indicate there's always a surplus of water.