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Geothermal needs A LOT of freshwater, to the extend it can cause a local water crisis, unless water injection is not used, which dramatically reduces available
by baybal2 5y ago
Geothermal needs A LOT of freshwater, to the extend it can cause a local water crisis, unless water injection is not used, which dramatically reduces available power.
Not to say, cheap, plentiful energy greatly increases water usage by itself.
In Pakistan, every farmer now has powerful immersible pumps with which they suck groundwater dry because of cheap solar panels availability.
- anonporridge 5y agoHow much loss happens in the system? Do you need a constant stream fresh water, or just a big initial injection?
- baybal2 5y agoDepends on the system used, but open cycle is the most common because of simplicity, and cost. > How much loss happens in the system? For an open cycle system it is 100% obviously.
- anonporridge 5y agoIs the waste water unusable, e.g. irradiated? Or can it be pumped back into the municipal water supply or reservoirs?
- _Microft 5y agoI think chemical contaminants are more of a concern than radiation.
- anonporridge 5y agoIn this case, shouldn't the operation be forced to treat the waste water anyway rather than dump it back into the environment? If it's dangerous for us to drink, it's probably damaging to wherever we dump it.
- baybal2 5y ago> Is the waste water unusable, e.g. irradiated? You will have to condense it from steam. Doable, but not without cost. It's also highly mineralised, and you will have to acid wash hardware frequently.
- dredmorbius 5y agoThere's typically an open loop and closed loop part of the system. The open loop transfers geothermal heat to the closed loop, the closed loop actually runs steam through the turbines. The reason for the closed loop is to keep mineralisation of the water to a minimum, as otherwise steam tubes and turbines are rapidly fouled. The open loop loses a significant amount of the initial water load, either through drainage or evaporative losses. Plants such as The Geysers, north of San Francisco in California, have had output reduced to about 40% of initial generation largely due to groundwater losses.
- petermcneeley 5y agoPakistan has quite a large daily temperature swing. You dont even need to dig or consume freshwater to get thermal energy.
- grkvlt 5y agosurely seawater can simply be desalinated on site with the plentiful electricity available, and the only fresh water needed would be during initial startup?
- baybal2 5y agoThat's possible if seawater is nearby, and you have a place to dump brine. And if you have freshwater nearby, it will always be more economical.
- int_19h 5y agoWhy fresh water specifically?
- baybal2 5y agoSalt water will clog the borehole with salt