The Hoover Dam has been one of the most powerful examples of impactful infrastructure in U.S. history — but a $3 billion makeover could make it even more effective.

The Los Angeles Department of Water and Power is moving to add a pipeline and pump station to the dam, and that pump station would get its power from alternative energy sources. Politics and environmental concerns could stand in the way, but advocates hope it could be a reality by 2028.

New York Times reporter Ivan Penn wrote about the proposal in a piece titled The $3 Billion Plan to Turn Hoover Dam Into a Giant Battery, and he joined The Show to talk about it.

GOLDSTEIN: Ivan, how would this plan to modify Hoover Dam work in the most practical sense?

IVAN PENN: The basic concept is actually not new. We have a number of hydro plants that act as pump storage, but those technologies typically operate where the generator water goes down from a reservoir and flows to a turbine, spins it, and then electricity is used to spin that generator in the opposite direction and pull the water back up to the reservoir to flow back down again at a later time. This technology would not touch Hoover Dam, which is not pump storage. It's just a generator. The water flows down and spins the turbine, but does not come back. The proposal is to place, basically, a pipe further down in the Colorado River with a pumping station separate from Hoover Dam and power that pump with renewable energy, particularly solar and also possibly wind, put the water back up behind the dam into Lake Mead so that it can flow back down and generate more electricity later. So that's the basic technology.

GOLDSTEIN: Now strictly from an engineering standpoint, that sounds complicated and yet, is it as complicated as it sounds?

PENN: It does sound a bit complicated, but if you sort of view it this way — all you're doing is, sort of, putting a straw in the river and pulling water up behind the dam. But, in terms of energy storage, it's more of what we call energy transference. So we have an enormous amount, in California, of excess solar and wind, particularly during the springtime. Unless we either shut those solar and wind farms off, or California literally giving away or selling at what they call "negative prices" — basically paying other states to take the power — you endanger the grid of being overloaded and causing blackouts in the same way that having insufficient power would cause a blackout. So what this will do is to take that excess solar and wind, and power the pump station to send water back up into the reservoir for a later time. That's just a way of storage, and you release the water when you need more power at periods of high demand.

GOLDSTEIN: According to the folks at Los Angeles Water District you talked to, they said the productivity of the dam would increase. I was surprised. Maybe I shouldn't be, but I was surprised that currently the dam only operates at about 20 percent of its potential. So this would seem like a good way of using more of that in a more efficient way. How big a part of the argument is that?

PENN: Well it's a significant part because you have two factors at play here. Part of the reason why the dam operates at 20 percent, some would say well, Lake Mead, the water has depleted significantly, which is an issue. But one of the really big issues is, if you release too much water from the dam at any given time, that water could potentially flood the towns that are downstream from Hoover Dam. So the idea of pumping the water back prevents that flooding. You're pumping the water back so you can increase the capacity from 20 percent, some projections have been to suggest as high as 45 percent, which is a significant, obviously, increase in the potential. But the flooding issue is a significant factor in that you release too much water, you potentially flood those towns downstream.

GOLDSTEIN: There's obviously some great enthusiast for the project or it wouldn't have gotten this far, but based on your piece, there's also concern that there could be a negative impact on the environment and even tourism. I wasn't thinking of tourism. Can you give us some background on those?

PENN: Absolutely. So, no matter what, you're going to affect the landscape there because you would be installing a pipeline to pump the water back. So that's going to affect the landscape and the environment. But also, you are pulling water out of the river, and depending on the location, if the water depth is insufficient, you run the risk of affecting marine life, and then you have boaters and people fishing on the lake, and that would be affected by it as well. So they're looking for a depth where recreational activity isn't affected and that marine life isn't affected.

GOLDSTEIN: Whether the practical details, of course you always hear about the devil being in the details, but as far as a concept, as far as an idea, does this make sense? Is it a smart plan to most?

PENN: There are many engineers that think that this is almost a no-brainer because Hoover Dam is not going anywhere anytime soon, and if it were to, then obviously we'd have more concerns than excess renewable energy. It's not a complicated concept, engineering-wise. So on those levels, it makes sense. The critics are arguing, there are some who have concerns about pump storage in general — silt build up, how much does this affect the towns and the river itself downstream. They're concerned about those kinds of impacts. It's not just simply, here's a workable idea. There are no hurdles. There definitely are some challenges, both environmentally politically and economically. The proposal right now would place it at about $3 billion.

GOLDSTEIN: Ivan Penn covers alternative energy for the New York Times, and we've been talking about his recent story The Three Billion Dollar Plan to Turn Hoover Dam Into a Giant Battery.