Is It Time to Rethink Hydro?

It’s hard enough for each country to figure out how to supply its people with enough electricity using sources that are readily available locally. Getting every country to pivot to just a few sources prescribed by a handful of academics is looking to be as hard as Ross pivoting a couch.

Maybe it’s finally time we rethink hydro.

Background: Hydropower has quietly been the low-carbon backbone helping many countries produce low-emission power for decades. According to the International Energy Agency, hydro provides roughly 17 percent of global electricity. Mostly in dam form.

• The largest in the world is the Three Gorges Dam which consumed 28 million cubic meters of concrete to build and flooded an area the size of Toronto for its reservoir.

Besides the flooding of many sensitive ecosystems and their huge use of concrete, dams notoriously emit methane from all the drowned, decomposing vegetation. But hey, at least the lil fishies probably love them.

Narrator: “They don’t. Fish hate dams.”

So what’s the case for hydro?

Two words: it works.

A quick glance at the 20 countries with the lowest-carbon-intense grids around the world shows a high degree of hydro use. Of the twenty, just 2 don’t have hydropower as their single largest power source: France, courtesy of its Cold War nuclear development program, and Kenya, sitting on East African Rift geothermal rocks so hot they’re practically a Kid Rock anthem.

The 20 countries with the lowest power carbon intensities

And while the price tag on large hydro projects will make any developer squeamish, over the long term, they provide cheap and stable electricity to citizens.

As of 2021, more than sixty countries around the world have hydro as the largest source of electricity and many of them have both low prices and low carbon intensities.

Top electricity source, carbon intensity, and grid carbon intensity of every country

Hydro has historically performed much better than intermittent renewables, which often don’t bake in the additional costs of energy storage and interconnection prices that grow exponentially with adoption.

But what about the fish?

Good news on this front. New generations of water turbines have been designed specifically for the benefit of fish.

• A study by the peer-reviewed American Fisheries Society found 100 percent of eels survived modern water turbines compared to just 40 percent with traditional designs.

Other issues: While there are still concerns about the huge areas required for flooding, developers have woken up to the fact that all renewables have significant land impacts, with increased mining and extraction required for material-intensive wind and solar projects.

And while the methane is an issue, it looks to be overblown. According to Environmental Science & Technology, there are initial methane releases from new hydro reservoirs, but they generally settle down to become stable, low-emission power supplies similar to wind and solar.

Bottom line: Ten years ago, nuclear was out of fashion but is now back in vogue. The next ten years could see the same shift for hydropower, with many of its stated issues looking either to be resolved or overblown.