One question I have is whether there are inexpensive things that can be done to raise electrical production from existing hydroelectric sources--does anyone know?

A question I raised with Bureau of Reclamation engineers at a hydro-electric conference a few years ago.

Generally speaking, US Gov't dams have 1920s to 1950s/1960s design turbines, said turbines are poorly maintained (wear on blades reduces % efficiency below design %), and the ratio of "spill water" (water let over dam during high water without producing power) is based on economics of when the dam was built.

They estimated that the US Gov't could easily get 5% more electricity with economically justified steps. (Raise maintenance to a high standard, use newest tech in generators & turbines (say 2% improvement since 1950s), add smaller generators for low flow & to reduce spill##) Give new marginal large hydro power the same value as wind and that % grows.

Example, house power (internal use) at Hoover Dam is a couple of Peltons (1 or 2 MW from vague memory) that have not been touched since built. My SWAG is rebuilding them could up efficiency at least 10%.

Ontario is in midst of major improvements at Niagara Falls (Sir Adam Beck)#. 14.4 m diameter tunnel will reduce friction losses, new/enlarged power plant will reduce the time that water spills unused (above requirements ) from 40% to 15%.

BTW, I strongly urge a recalculation of the water spilled for tourists at Niagara Falls. Reduce hours & days of max spill flow, reduce the max spill flow, reduce the overnight spill flow, enlarge Sir Adam Beck (Ontario) even more and enlarge Robert Moses (New York). Reducing spill at Niagara Falls (now 4+ GW of hydro) is cheap, easy, quick renewable energy and = to one years new wind (roughly).

Best Hopes for more Hydro,

Alan

#
http://www.opg.com/power/hydro/new_projects/ntp/index.asp

## Example. Dam has two 40 MW generators. At low flow, they either shut down or operate at dismal efficiency. Add 6 MW generator. More efficiency at low flow and an extra 6 MW when water would otherwise be spilled. Relatively easy (sometimes) to add small generator to powerhouse with two large generators.

Also 40 MW + 6 MW can be more efficient than 2 x 40 MW at some mid-range flows.

I believe that the article missed that Manitoba has 5 GW of new hydro they are actively shopping. Wisconsin bought 800 MW of that 5 GW. Their scheme uses the "other Great Lake" Lake Manitoba as the storage reservoir.

I ran into this issue trying to add up all the electricity that is produced (immediate and over time) in the U.S. When you get into billions and trillions, you have to be really careful with the comparisons.

If you do it all in petawatts (1 petawatt = 1,000 trillion watts), and not mix watts with watt-hours ...

Big Gav says North America (3 countries) has 4,800 TWh (trillion watt hours) of capacity, or 4.8 petawatt hours.

Gail's charts say the U.S. alone (one country) has 1,000 gigawatts (= billion watts) of capacity which equals 1 terawatt which equals .001 petawatts immediate, for the U.S. alone

Gail's other chart says 4,000 BKh (billion kilowatt hours) which equals 4 trillion watt hours which equals .004 petawatt hours for the U.S. alone

I don't think all these are close to adding up. :)

Gail the DOE , 2003 study I have linked to in article shows that many dams don't generate any power or can be upgraded to produce additional power for $1600/kWh capacity( 2003 figures). This is not much more than NG peakers, but very little running costs