The largely theoretical study, published Wednesday in the journal Nature, examined 185,000 glaciers around the world and determined where environmental, technical and economic factors would allow for the building of dams to harness both the power of glacier melt and the value of water itself. If all such sites were tapped, the amount of electricity generated would equal 7% of the world’s total electricity consumption in 2015, or 35% of the world’s output from dams.
“Building a dam at every glacier location is neither realistic, nor sustainable, nor desirable,” the authors emphasize. The value in such an ambitious exercise in virtual civil engineering is worth considering given, the potentially “important contributions to national energy supplies, particularly in High Mountain Asia,” a region with so much ice it’s informally called the Third Pole.
In addition to the massive amount of hydropower, the authors found the glacier basins could hold a combined 48% of the runoff from current glaciers. That’s especially important in arid regions, where such reserves serve as a hedge against future water scarcity.
Almost a third of the potential power comes from 1,000 of the 185,000 sites, and the 10 largest glacier basins that could be dammed are in the U.S., China, Canada and Nepal.
The hydropower industry is already facing long-predicted higher costs, as operators expect to struggle with both extreme weather and falling capacity in the coming years.
Large hydropower projects, however, are rarely planned, financed and built without considerable debate and opposition, which is why the researchers selected sites with an eye towards minimizing environmental impact instead of maximizing potential revenue. The team generated rough cost estimates for each location that included the dam itself, power stations, operations and transmission to the nearest grid. About 60% of the theoretical maximum of plants could have production costs below 50 cents a kilowatt-hour.
“The uncertainties are high,” said Upmanu Lall, director of the Columbia Water Center who was not involved in the study, “and it is rather unlikely that, politically, new reservoir construction will be allowed in most countries.
