Why can’t we install small water turbines in California’s expansive aqueduct system?


Why can’t we install small water turbines in California’s expansive aqueduct system?

In: Technology

They already do, but… California aqueducts actually *consume* more energy than it creates. Anything created by the water’s potential energy via hydroelectric plants go right into pumping that water up slopes (**i.e:** Tehachapi Mountains).

You can. Adding turbines to canals is done all over the world. It’s just a question of whether there’s any value to doing it.

To generate hydro power you either need a lot of water (which is why most hydro dams are massive,) or a lot of energy in the water (so-called run of river plants will divert water 300 metres about the powerhouse.) A small irrigation canal likely doesn’t have enough flow or enough energy to generate enough power to justify the expense associated with installing the turbine and associated wiring.

I will add that most people don’t really have an understanding of how water (or wind) energy gets converted into electricity.

Slightly complex version: Whenever you spin a turbine, if you have no electricity flowing out of it you only need to overcome the inertia of the machine itself. However as you start increasing the electrical energy being output by the generator, you will have a counter force that works against your mechanical torque to slow down the generator and you need to push harder to get it to spin.

Easier version: the more energy you want to get out, the more the generator fights you. This put a hard limit into how much energy you can extract from a given pipe.

Energy pulled out of the water is energy that isn’t available to get the water wherever it is going.

If you don’t particularly care about the water getting downstream, hydro is “free” energy. But in an aqueduct system we do care about getting the water to its destination.