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Comment by gallexme | Hacker News Reader

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gallexme·

There many water dams which feed whole cities

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We really should stop using the same word for two things with such different characteristics.

Hydro/geothermal: nice steady power but not easily available everywhere.

Wind/solar: available everywhere but variable output.

Obviously it's easy to run a city on "renewables" if you have a convenient dam, but if you only have wind/solar it's more challenging.

Dams are literally terrible in terms of ecological impact. The sooner they are all gone the better.

as opposed to figuratively terrible?

The ecological impact of dams is totally local, but the ecological impact of CO2 is global. If we were to power the entire earth with hydro, the local damage to ecosystems would be a very small price to pay indeed.

Dams are obviously better than fossil, but I think a case can be made that fusion would be better than dams.

Also, using a fossil plant is harmful, using a dam is not. The damage was done when it was built.

I've seen arguments that some dams where the water level varies a lot produce a lot of GHG's due to decaying plant matter.

But yes, in general compared to fossils it certainly wins.

Any specific good material that I could read more on this?

A lot of the impact can be mitigated by building fish pass channels, building new habitat such as compensation channels, and controlling the rate of change of water levels.

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