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A comment on Wind and solar are cheaper than thought, admits UK government. Parent comment

Re:Wind and solar are cheaper than thought, admits UK govern... by soperj on Thursday August 27, 2020 @02:44PM (#24297110)
>has 0 pollution outside of initial dam construction, is perfectly safe.

These are both demonstrably untrue.

1st, due to methane releases of decaying plant matter in the flood zones depending on what is flooded Hydro can actually produce over double the emissions of the worst coal plants, annually. For example the Curuá-Una dam in Pará, Brazil, has produced three-and-a-half times more emissions than an equivalent generating plant running on oil.

Based on what was flooded by the WAC Bennett dam in BC, BC likely has more GHG emmissions in their energy mix than Alberta.

And based on the size of the reservoirs(some of the largest in the world) in Quebec & that the flooded mostly boreal forest & peat land, that is also true for Quebec.

2nd, Dams breaking have caused a lot of deaths: https://en.wikipedia.org/wiki/1975_Banqiao_Dam_failure

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Re:Wind and solar are cheaper than thought, admits UK govern... by joshlemer on Friday August 28, 2020 @09:54AM (#24304825)
>1st, due to methane releases of decaying plant matter in the flood zones depending on what is flooded Hydro can actually produce over double the emissions of the worst coal plants, annually. For example the Curuá-Una dam in Pará, Brazil, has produced three-and-a-half times more emissions than an equivalent generating plant running on oil.

Thanks for the info, I had no idea. Is this a long term effect where reservoirs will continue to emit CO2 into the long term future, or is it just a one-off cost to transforming land into a lake? If it is just a temporary source of CO2, how long does it take for the emissions to peter out and at what point will the hydroelectric dam become even with coal in terms of emissions?

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Re:Wind and solar are cheaper than thought, admits UK govern... by soperj on Friday August 28, 2020 @12:36PM (#24306893)
It's a long term effect. Trees can take over 100 years to break down in an aerobic environment. Decomposition time doubles in an anaerobic environment.
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