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From the article: "The LucidPipe™ Power System uses the gravity-fed flow of water inside a PWB pipeline to spin four 42” turbines that are now producing electricity for Portland General Electric (PGE) customers under a 20-year power purchase agreement (PPA) with the utility"

No pumping required.

Presumably Portland's reservoirs are located somewhere uphill (in the Cascades even?) so this would be exploiting a natural gradient.

The reservoirs are indeed elevated around here -- washington park, mt tabor, powell butte -- so it's all gravity fed.

Gravity.