Why is the concept of pumping water uphill not commonly used as a source of electricity generation, similar to pumped-hydro systems?
Last Updated: 17.06.2025 03:23
There are about 4 places where they have large pumped hydroelectric storage in California. A couple more in the TVA power system, one in Missouri that I know of.
Why do this? Because they can get a return of about 80% of the power they used pumping the water uphill. How can that make money?
While pumping the water uphill, they use huge amounts of power, like 475 MW per hour in the TVA project, and similar amounts in other projects. So if you have 4 pumps moving water uphill at 400 MW each, that is like using as much power as my home uses in 1 month in about 40 minutes. I pay about $130 a month, so about $200 a hour to pump the water uphill.
But hydroelectric can have problems too. Lake Shasta in California was down by over 200 feet of water level around 2022. They where not able to make affordable hydroelectric power for a few months. Then the winter of 24 happened, and the lake was filled again.
They use very low priced power to move the water uphill. Think about $0.05 per KW.. Then when peak power is needed, and the Power Utility is willing to pay $0.45 per KW for that power, they reverse the pumps, and produce electricity. So even if they use 4,000 MW to pump the water uphill at $0.05 per KW, and then get back only 3,000 MW when they generate power at $0.45 per KW, they are making a big profit.
Why not more pumped storage locations? They are actually kinda difficult to find a great pumped hydroelectric place to install them. I can think of a couple of ideal locations. But they are also very expensive to build them. About $1 Billion.
And the hydroelectric generators do not need to be charged to make the power. They rely on rain and snow filling the upper reservoirs and having water to flow downhill into that lake. So basically no fuel cost to run it.