4 ms·

You don't need battery storage if you've got hydro. You need solar. Make hydro the backup, fill reservoirs as your reserve and sell extra energy when they're

You don't need battery storage if you've got hydro. You need solar. Make hydro the backup, fill reservoirs as your reserve and sell extra energy when they're nearly full.

tialaramex 7mo ago
I can see this makes sense especially for medium term storage. A lot full of batteries is great for the next ten seconds, next ten minutes, even to some extent the next ten hours, but it surely doesn't make much sense to store ten days of electricity that way compared to just keeping the water behind a dam. We know that many of the world's large dams are capturing snow melt or other seasonal flows, running them only when solar or wind can't provide the power you need lets you make more effective use of the same resource.
- colechristensen 7mo ago
  Except for very short term peaks (less than 15 minutes-ish) it doesn't make any sense at all to use hydro to charge batteries. You've got a dam, you might as well let water through later than incur the losses of a round trip to batteries and back to the grid.
- hvb2 7mo ago
  Except that in many cases there's people living downstream doing agriculture using that water for irrigation. There's just this tiny dispute about that in the nile delta between Egypt and Ethiopia https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Dam https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Da...
znkynz 7mo ago
There are two types of hydro - run of river, and ones with large lake storage. You need the ones with large lake storage, rather that the ones with a lake to build a head.
XorNot 7mo ago
Pumped hydro storage only holds about 8-12 hours of power. To be economically viable to build you need to cycle it daily. It uses enormous amounts of land and capital to build, and is ongoingly dangerous in a unique way. If LiFePO4 can do 4 hours at full output already, and be placed anywhere using volume manufacturing to expand, then batteries are straight up better. Pumped hydro is an expensive dead end.
- colechristensen 7mo ago
  I'm not talking about pumped hydro.
  - XorNot 7mo ago
    The you're talking about a geographical limited, extremely finite resource with a substantial ecological footprint.
    - colechristensen 7mo ago
      Yes... countries with extensive existing hydro using less of it by displacing it with solar, ultimately enabling the dismantling of some of the dams.
- peterashford 7mo ago
  In NZ we're discussing pumped hydro in Lake Onslow which will provides months of backup for the country
  - hunterpayne 7mo ago
    Each way you move the energy costs you 50% in efficiency. Which is why pumped hydro has to have a 4x different in the price of energy in vs energy out to make it economically viable. That's why PG&E almost never uses their pumped storage. Only on days where the mid day price of power is very low does it make sense. And keep in mind that California is the ideal place for pumped storage. I seriously doubt that NZ has a 3x duck curve in its energy demand.

You don't need battery storage if you've got hydro. You need solar. Make hydro the backup, fill reservoirs as your reserve and sell extra energy when they're nearly full.

tialaramex 7mo ago

I can see this makes sense especially for medium term storage. A lot full of batteries is great for the next ten seconds, next ten minutes, even to some extent the next ten hours, but it surely doesn't make much sense to store ten days of electricity that way compared to just keeping the water behind a dam. We know that many of the world's large dams are capturing snow melt or other seasonal flows, running them only when solar or wind can't provide the power you need lets you make more effective use of the same resource.

colechristensen 7mo ago
Except for very short term peaks (less than 15 minutes-ish) it doesn't make any sense at all to use hydro to charge batteries. You've got a dam, you might as well let water through later than incur the losses of a round trip to batteries and back to the grid.
hvb2 7mo ago
Except that in many cases there's people living downstream doing agriculture using that water for irrigation. There's just this tiny dispute about that in the nile delta between Egypt and Ethiopia https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Dam https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Da...

znkynz 7mo ago

There are two types of hydro - run of river, and ones with large lake storage. You need the ones with large lake storage, rather that the ones with a lake to build a head.

XorNot 7mo ago

Pumped hydro storage only holds about 8-12 hours of power. To be economically viable to build you need to cycle it daily. It uses enormous amounts of land and capital to build, and is ongoingly dangerous in a unique way. If LiFePO4 can do 4 hours at full output already, and be placed anywhere using volume manufacturing to expand, then batteries are straight up better. Pumped hydro is an expensive dead end.

colechristensen 7mo ago
I'm not talking about pumped hydro.
- XorNot 7mo ago
  The you're talking about a geographical limited, extremely finite resource with a substantial ecological footprint.
  - colechristensen 7mo ago
    Yes... countries with extensive existing hydro using less of it by displacing it with solar, ultimately enabling the dismantling of some of the dams.
peterashford 7mo ago
In NZ we're discussing pumped hydro in Lake Onslow which will provides months of backup for the country
- hunterpayne 7mo ago
  Each way you move the energy costs you 50% in efficiency. Which is why pumped hydro has to have a 4x different in the price of energy in vs energy out to make it economically viable. That's why PG&E almost never uses their pumped storage. Only on days where the mid day price of power is very low does it make sense. And keep in mind that California is the ideal place for pumped storage. I seriously doubt that NZ has a 3x duck curve in its energy demand.