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Comment by ProllyInfamous | Hacker News Reader

Texas needs more (any?) pumped-storage hydro (a non-chemical, gravity-fed battery) to store all this renewable energy.

TVA (similar in size to ERCOT, mostly within Tennessee) is about to begin its second such facility, after Raccoon Mountain [0]. Run-of-the-river facilities exist (including two in TVA's jurisdiction), which are capable of pumping water "up" the dam (for later use during peak loads) — perhaps LCRA might explore the feasibility of this?

Regardless of how the energy is stored, it might also (eventually) make sense to join Eastern/Western interconnects (and thereby "store" the energy outside of Texas). But I know ego/"Texus"/pride mentality exists (having grown up in Austin), so I won't hold my breath on accepting Federal regulations...

[0] wikipedia.org/wiki/Raccoon_Mountain_Pumped-Storage_Plant

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Why would pumped storage be better than the massive amounts of batteries being added right now? Batteries scale small, scale big, can be put where there's already transmission, can be put at either sides of grid congestion to lower that congestion, can regulate frequency, deliver reactive power, and be moved to new locations if the grid changes and they could be better deployed elsewhere. Literally a Swiss Army knife that can grow to whatever size is needed, and they can be thrown up in months as opposed to years.

I'm not sure if hydro could compete on price any more, either. Batteries are so cheap.

I don't really know if there is somewhere in Texas that works geographically; but the idea is if you have a good spot you essentially get an arbitrarily large store for the price of one dam.

At some point you get limited by fill/discharge rate, but the cost of storage in a big pumped hydro is still pretty cheap.

Have you ever been to Texas? 'one dam' doesn't even begin to describe the place. If you're at a body of water, look around. There's a dam. All lakes are artificial with the exception of Lake Caddo.

Lake Travis already has a power plant and is rarely every full for example. No one is going to start using pumped hydro there because there is no extra water to pump.

To add to this TX and the SW USA are currently (been 20 years now) experiencing an extended drought. Water levels are at an all time low; many lakes are almost dry; and even the aquifers are getting a bit frumpy. As sidewndr46 said, ain't no water to pump.

Very briefly visited, (I'm an Aussie) I saw lakes and dams; but I never really had a look to see if there was a good spot to build a pipe between or to create a new lake.

You don't actually need an excess of water, you need to be able to move enough between lakes though. You are not using any extra water from the system by adding pumps.

That's the real determining factor right, places with cheap big pumped hydro projects ideally already have big dams that are not full, so from that point it works. But then you need a reasonable amount of elevation between reasonably close lakes (or ideal new spots).

Pumped hydro is a pretty cool solution, but it requires very specific geography and water supply combinations that are unfortunately relatively rare. I'm not that familiar with Texas's water and elevation situation, but it seems less obviously a good candidate than the TVA. Don't get me wrong, pumped hydro is an awesome solution where it works, but it's not easily deployable in the way that batteries are.

ERCOT is roughly 3x bigger than TVA in terms of both energy demand and service area.

They said similar. Similar in the same way a flat arid landscape that is the second largest in size in the union compares to a mid-sized state with mountains and more annual rain fall and is heavily forested with an average temp 20° lower. You know, not the same, but similar. Maybe they meant simile?

TVA is a so called "Independent agency of the United States government", so no. Not even close. ERCOT is a state level entity

What happens to your battery when you are in the middle of a drought and your "battery" doesn't have enough water in it to operate as a battery?

You don't need to use a river for pumped storage, you can even have a (mostly) closed-state solution that pumps water back and forth between two holding tanks.

What does a river have anything to do with what I asked?

You seemed to think that the water would be susceptible to drying up in drought conditions, presumably because the river feeding it would dry up.

I'm seeming to think nothing while knowing that the drought conditions slow the replenishing of the water levels, but the water levels are lowering faster than just evaporation because Texas lakes are water supplies for the cities. That drains the lake levels much faster than just being in a drought.

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