Northfield Mountain is a great plant. The company I work for used to own it before we foolishly sold it off. A pension plan bought it, which is a good indication of how stable it's economic outlook is. It's also an important black-start resource in the northeast.
The difference between Northfield and Lake Mead / Hoover Dam is that dedicated pumped-storage plants have two reservoirs: upper and lower. They are generally able to move water between them as needed with few restrictions because there is no downstream water user who's going to suffer damage because water was released from the upper reservoir (or taken from the lower reservoir).
The Colorado River is pretty much the ultimate opposite case. The existing Hoover Dam operations are dictated entirely by downstream flow requirements. If water has to flow downstream (because it's needed by agricultural users), it flows, and power generation follows. If flow needs to be restricted for flood control, power generation is reduced accordingly. Other than emergency spillways, there's no way for water to flow downstream except through the turbines, so there's no flexibility based on the needs or conditions of the power grid. In power industry terminology this is called a 'must-run' resource.
This article doesn't address that at all, although I imagine that if there is a serious engineering paper proposing this that it would look at the consequences of this in detail. It's extremely questionable to invest this scale of money in an energy storage resource that will likely never attain its full operational potential because the operator would not be allowed to ramp up or down arbitrarily. Batteries are more expensive - right now - but far less risky and can easily be deployed to any location, in precisely the size and scale required, with minimal financial risk or exposure to changing climate patterns.
The difference between Northfield and Lake Mead / Hoover Dam is that dedicated pumped-storage plants have two reservoirs: upper and lower. They are generally able to move water between them as needed with few restrictions because there is no downstream water user who's going to suffer damage because water was released from the upper reservoir (or taken from the lower reservoir).
The Colorado River is pretty much the ultimate opposite case. The existing Hoover Dam operations are dictated entirely by downstream flow requirements. If water has to flow downstream (because it's needed by agricultural users), it flows, and power generation follows. If flow needs to be restricted for flood control, power generation is reduced accordingly. Other than emergency spillways, there's no way for water to flow downstream except through the turbines, so there's no flexibility based on the needs or conditions of the power grid. In power industry terminology this is called a 'must-run' resource.
This article doesn't address that at all, although I imagine that if there is a serious engineering paper proposing this that it would look at the consequences of this in detail. It's extremely questionable to invest this scale of money in an energy storage resource that will likely never attain its full operational potential because the operator would not be allowed to ramp up or down arbitrarily. Batteries are more expensive - right now - but far less risky and can easily be deployed to any location, in precisely the size and scale required, with minimal financial risk or exposure to changing climate patterns.