4 ms·
Where does the energy go when it is not being extracted with this method? I understand that the energy is extracted from the movement of ions between reservoir
by marcan_42 7y ago
Where does the energy go when it is not being extracted with this method?
I understand that the energy is extracted from the movement of ions between reservoirs of different salinity. If you're just letting the two sides mix, as they do naturally, where does the energy go instead? Is it released as heat?
- marcosdumay 7y agoIt converts thermal energy into usable electricity (that is, the water gets cooler), at the cost of the increased entropy in the mixing of fresh and saline water.
- Accujack 7y agoAlso, the environmental cost of keeping river estuaries blocked by impermeable membranes so you can maintain the gradient of salt/fresh water.
- sigmaprimus 7y agoAlso why bother with a membrane, the fact is river water for the majority of the year is either warmer or cooler than the typically constant ocean temperature. Two bodies of water at different temperatures plus a heat pump can be quite effective at producing energy, no?
- semi-extrinsic 7y agoUnfortunately heat pumps are not very good at producing power from small heat differences. In industrial plants, any waste heat stream that's below 100C is considered "low grade" and mostly used for heating office buildings etc.
- sigmaprimus 7y agoAhh, I did not know that. My experience is through my HVAC course where it only covered heating applications not power generation. Still the way a heat pump in a HVAC system works you turn a small temperature difference into larger difference through the "A" coil, essentially compressing the warm air to make it hot, but I guess this does not scale well.