Questions tagged [hydroelectric-dams]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1
vote
0answers
30 views

What's the smallest hydropower plant that can blackstart a grid?

One of the most underrated capabilites of classical, large-scale hydropower plants is their ability to "black start" a dead electric grid. I'm not going to go into details on the blackstart ...
0
votes
1answer
35 views

Why did they move ancient Egyptian temples to prevent them from water damage instead of encircling them with a dam?

Specifically I'm talking about Abu Simbel temple and Philae temple. Which are close to a reservoir created by Aswan dam. It seems to me easier to build a dam than to move a temple.
1
vote
5answers
104 views

Why do dams deplete rivers?

I have often heard of cases where dams reduce the flow rate of rivers downstream. This makes sense in cases where some of the water that is captured by the dam is used for irrigation and such, but in ...
-1
votes
1answer
77 views

What specific technical concerns exist for China's Three Gorges damn on the Yangtze river?

Recently, many people (specifically geopolitical and financial analysts) have pointed out that there is a serious concern about China's Three Gorges Dam breaking and causing catastrophic flooding that ...
3
votes
1answer
2k views

How and WHY does the tension in an arch dam or bridge change as the degree of curvature and radius of curvature change?

Arch bridges operate according to the following (I am assuming arch dams are the same): Tensional force in arch bridges are virtually negligible. The natural curve of the arch and its ability to ...
4
votes
2answers
127 views

Does a spillway failure have different consequences versus dam failure?

I noticed this Tweet about the Oroville Dam concerns this week: Seems most media is not emphasizing/noting the distinction. Is there a difference in the consequences of a spillway failure? Seems ...
7
votes
2answers
4k views

Why do hydroelectric plants use turbines instead of an efficient 'water wheel' configuration?

I have been thinking about hydroelectric plants and I have been wondering why they are built the way they are. As in understand it, a stream of water is sprayed at a turbine, located at the bottom of ...
23
votes
5answers
7k views

Why don't hydroelectric plants use cascades of turbines instead of single turbines?

In a gas turbine engine there're multiple sets of blades - one set after another and combustion products pass all the sets and each set of blades gets some of the power. This increases utilization of ...