New water storage being created in CA. The water needs to be pumped to be used if/when a drought arrives.
"Hydro will fulfill half the energy needs for pumping. "Renewable sources" will provide the other half."
I have not heard of using solar panels to pump water and if that can be done efficiently in large volume it would be interesting. Seems kind of a stretch for solar panels?
Sites Reservoir: Water for Dry Years Now more than ever, California needs to address its statewide water management challenges by implementing innovative solutions that address our state’s need for a sustainable water supply. The state’s water infrastructure is getting older and stressed beyond its
sitesproject.org
Dam advocates are trying hard in California. The Sites project, and one near us have been floating around for years, with occasional bursts of activity. The latest price tag on our local one was so high, that they elected to raise a nearby dam (Los Banos) a few feet for a vastly larger increase in storage.
Yes, we need ways to smooth power demand and supply to account for variations in both. Pumped hydro is a solution. So are liquid batteries, aka flow batteries, thermal storage, batteries and EVs. At the moment, most pumped hydro is not even close to competitive with the alternatives on a cost /MWh. I think that's why the Sites advocates are pushing the potential for multiyear water transfer as an advantage. It is hard to price, and easy to make it sound as if it would be a profitable investment. However, that really isn't the case. Demand reductions, consumer, and agriculture, are much, much cheaper.
If you are interested, check out David Sedlak's new book on water sustainability;
and his older book;
(Disclaimer: I know the author)
Pumped hydro works best for a large height difference between the upper and lower reservoirs. The Sites dam isn't a great candidate to my mind, as it is flat, therefore prone to evaporation, and not much higher than the Sacramento river. Great for low energy filling, but not good at all for energy, especially when the water that cost energy to pump up evaporates.
Good discussion here;
Developers argue that pumped storage hydro can help meet climate change targets, but no new schemes have been built for decades.
www.bbc.com
The British have issues with demand power contracts that don't exist here in the US, but many of the other details are relevant. Pumped hydro does represent a reasonable way to store many hours or days of power, but at the end of the day, it is a $/MWh item. If it is only used a few times a year, the price per MWh becomes enormous. If the site is designed for day / night use, then maybe it can support six hours of production, so a better $/MWh, but it does mean that they have to buy power, pump water up fast enough to have enough to use for six hours. It also means that the site is unlikely to be great at longer term power production. Like any piece of equipment that isn't used often the cost per hour of use can be high, making it less competitive.
In my opinion, most of these projects are not adequately priced in advance, unrealistic assumptions are made about the cost, the number of jobs, the lifetime, and what the deconstruction cost will be. These are the reasons that the US has so many older, failing dams, with nobody left around to fix /deconstruct them, except taxpayers.
All the best,
Peter
calmatters.org
