While cleaner than fossil fuels, large-scale hydropower dams come with steep social and environmental costs of their own.
An extraordinary plan to revive the Dead Sea could ease tensions among Israel, Palestine and Jordan. Or it could create an environmental disaster.
Build new, low-impact hydropower facilities but keep the old: Large dams already in existence can be improved.
Hydropower will never be the complete answer to emissions-free energy production in the U.S., but a strong case can be made for it becoming a useful part of the answer.
Looking at the untapped potential for hydropower to supply the U.S. with carbon-free electricity, Lea-Rachel Kosnik finds ample opportunities for expanding hydro.