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It's also a misconception to equate huge-reservoir hydro with all hydro. The Norwegians have incredibly high head, phenomenally efficient hydro in the mountains

by cwal37 12y ago

It's also a misconception to equate huge-reservoir hydro with all hydro. The Norwegians have incredibly high head, phenomenally efficient hydro in the mountains with minimal environmental impact. We have run of river hydroelectric in the states that diverts some water via penstock, as well as canal-based systems and those that utilize Army Corp dams. In fact, there is significant non-powered dam resource available: http://nhaap.ornl.gov/content/non-powered-dam-potential http://nhaap.ornl.gov/content/non-powered-dam-potential I'm actually working on national-level hydro assessments at a national lab. We don't really predict more huge reservoir installments, but there is plenty of capacity out there. These set-ups (particularly non-powered dams) are also generally pretty cheap per kWh generated over their lifetimes (which in some cases reaches 70+ years).

EdwardDiego 12y ago
> We have run of river hydroelectric in the states that diverts some water via penstock Do you have wildlife issues to consider in the design? E.g., are the dams on rivers fish migrate up?
- cwal37 12y ago
  Well, run-of-river installations actually don't have dams, and you can prevent most fish with just some mesh, so you're avoiding that impact entirely.
  - EdwardDiego 12y ago
    Ah cool, that's good to hear (so long as flows are sustainable, unlike some of our proposals for 'harnessing all that wasted water')
sbierwagen 12y ago
Why only 70 years? Does the dam actually crumble to pieces, or is 70 years how long it takes for maintenance costs to equal construction costs?
- cwal37 12y ago
  Some last longer, some die quicker, it depends on the conditions and upkeep for a particular installation. I threw out 70 years off the top of my head to demonstrate that they tend to last a relatively long time. It also depends on what you consider to be "replacement" vs. "repair". Sometimes all you have left is a concrete shell with rusted out turbine husks, in other cases you just need to replace a few parts. Hydroelectric generation (and water-power in general) has been around for a pretty long time, and there are a lot of different local implementations out there when you get into the details. The badger hydroelectric plant in Wisconsin is 86 years old, and that's just one I happened to know because I collected data on it recently. If you go further east in the states and then across the Atlantic, the plants can get older than that as well. http://www.kaukaunautilities.com/about_us/default.asp?CategoryNumber=7&SubcategoryNumber=1 http://www.kaukaunautilities.com/about_us/default.asp?Catego... EDIT: Oh, and in terms of cost, when planning out capital expenses most hydro projects are assuming a shorter lifespan than actual. I don't have numbers in front of me, but I feel like costs are generally accounted for a 20-40 year lifespan (weighted towards 20), although they do expect the plants to operate for 2-3x as long.

by cwal37 12y ago

EdwardDiego 12y ago

> We have run of river hydroelectric in the states that diverts some water via penstock Do you have wildlife issues to consider in the design? E.g., are the dams on rivers fish migrate up?

cwal37 12y ago
Well, run-of-river installations actually don't have dams, and you can prevent most fish with just some mesh, so you're avoiding that impact entirely.
- EdwardDiego 12y ago
  Ah cool, that's good to hear (so long as flows are sustainable, unlike some of our proposals for 'harnessing all that wasted water')

sbierwagen 12y ago

Why only 70 years? Does the dam actually crumble to pieces, or is 70 years how long it takes for maintenance costs to equal construction costs?

cwal37 12y ago
Some last longer, some die quicker, it depends on the conditions and upkeep for a particular installation. I threw out 70 years off the top of my head to demonstrate that they tend to last a relatively long time. It also depends on what you consider to be "replacement" vs. "repair". Sometimes all you have left is a concrete shell with rusted out turbine husks, in other cases you just need to replace a few parts. Hydroelectric generation (and water-power in general) has been around for a pretty long time, and there are a lot of different local implementations out there when you get into the details. The badger hydroelectric plant in Wisconsin is 86 years old, and that's just one I happened to know because I collected data on it recently. If you go further east in the states and then across the Atlantic, the plants can get older than that as well. http://www.kaukaunautilities.com/about_us/default.asp?CategoryNumber=7&SubcategoryNumber=1 http://www.kaukaunautilities.com/about_us/default.asp?Catego... EDIT: Oh, and in terms of cost, when planning out capital expenses most hydro projects are assuming a shorter lifespan than actual. I don't have numbers in front of me, but I feel like costs are generally accounted for a 20-40 year lifespan (weighted towards 20), although they do expect the plants to operate for 2-3x as long.