alt Hacker NewsI 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.