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Can Hoover Dam Become a Giant $3B Battery? (cleantechnica.com)
The Los Angeles Department of Water and Power wants to spend $3 billion to pump back the water that's flowing through Hoover Dam -- so it can flow through again later, during periods of peak energy demand. This generates a net profit for the dam's operators -- the pumping stations are powered by cheap solar and wind energy, while the dams are currently operating at just 20% of their capacity. An anonymous reader quotes Clean Technica:
The problem is that California has so much renewable energy available now, thanks in large measure to aggressive state mandated policies, that much of it is "constrained." That's utility industry speak for having to give it away or simply let it go to waste. In some cases, utilities in California actually pay other utility companies to take the excess electricity off their hands.
Why not store it all in some of Elon Musk's grid scale batteries? Simply put, pumped hydroelectric storage is cheaper than battery storage, at least for now. Lazard, the financial advisory and asset management firm, estimates utility scale lithium-ion batteries cost 26 cents per kilowatt-hour compared with 15 cents for pumped hydro storage. "Hoover Dam is ideal for this," Kelly Sanders, an assistant professor of civil and environmental engineering at the University of Southern California tells the New York Times. "It's a gigantic plant. We don't have anything on the horizon as far as batteries of that magnitude."
Why not store it all in some of Elon Musk's grid scale batteries? Simply put, pumped hydroelectric storage is cheaper than battery storage, at least for now. Lazard, the financial advisory and asset management firm, estimates utility scale lithium-ion batteries cost 26 cents per kilowatt-hour compared with 15 cents for pumped hydro storage. "Hoover Dam is ideal for this," Kelly Sanders, an assistant professor of civil and environmental engineering at the University of Southern California tells the New York Times. "It's a gigantic plant. We don't have anything on the horizon as far as batteries of that magnitude."
Sounds like due to renewables there is at times extra power that can be stored (by pumping water uphill.) You also need excess water to be pumped uphill. Does California also have this excess water? When you consider the value of the water, does it still make economic sense to put it back behind the dam? I don't know the answer or have an opinion on this, but I do keep hearing about water shortages in California, so it makes me wonder.
They got the cost right, but it's a cost for capacity not a cost added on to each KWh delivered.
The problem is... where's the lower reservoir? The Colorado River isn't going to run backwards for you.
Also:
I assume they mean 2,6 and 1,5 cents, respectively.
Exactly. The Hoover Dam is a national monument, and this idea is monumentally stupid. Large dams like the Hoover constantly let water through because it is required to keep the river flowing. So you would need to let more water flow through to keep the river flowing.
Even if it made sense you'd have to carve out a large lower reservoir near the base of the dam. That fact the "Cleantechnica' didn't even mention this is a testament to their prowess at energy solutions.
When looking at something of this scale, you can't use today's prices. I found several estimates of the rate of decline of cost in battery storage over the next few years and even the conservative ones put it at 70% of today's prices in 5 years. Since pumped storage is a very mature technology, it is unlikely to experience any decline.
The 15 vs 26 cent comparison in the article amounts to pumped storage being roughly 60% of the cost of battery storage right now. So, in roughly 7 years, the two should cross. And that doesn't take into account the likelihood of big advancements in utility scale flow battery storage which is likely going to replace lithium because it is not an application that cares about density or weight of the battery system so much as cost.
The likelihood of a project of this magnitude gaining all of its approvals and being completed in 7 years is slim to none.
This is just an attempt to slip some more billions into the old-money major construction industry.
It would be better to build much smaller scale projects with batteries placed closer to demand points. They would start coming online much sooner and each year the new projects can adapt to the latest, most cost-effective technologies. If you spread that same $3 billion over 15 years of battery buildout, the cost of the ones you're building near the end will be much less than that 15 cent per kWH mark and balance out the cost of today's expenditures. In addition, you'll be providing service within the first year. Mega projects always get eaten up by increased costs due to delays. A battery approach actually ends up having a decreased cost with delays.