It’s the beginning of the end for the era of mega-dam building in China. China Three Gorges Corp. on Monday turned on the first set of generators at the massive Wudongde hydropower plant, deep in the mountains of Yunnan province. About 170 kilometers (106 miles) downstream on the Jinsha River sits Baihetan, the last of its kind, scheduled to go into operation next year.

Now, China’s hydro industry is down-shifting toward smaller projects and pumped storage. Engineers have run out of the easiest locations to power massive sets of turbines and the falling cost of rival energy sources such as solar mean it isn’t worth moving on to more challenging locations.