Selecting a turbine

http://www.britannica.com/EBchecked/topic/609552/turbine/45669/Turbine-selection-on-the-basis-of-specific-speed

http://hydropower.inel.gov/techtransfer/pdfs/feasibility_studies_for_small_scale_hydropower_additions-16.pdf

A turbine is selected based on its specific speed.  The equation for specific speed is

N = specific speed

n = number of revolutions per minute

P = the output power

H = the head in feet

The available head determines what type of turbine will be used and the rate of flow determines the capacity of the turbine.  Hydraulic turbines are classified as impulse or reaction, reaction turbines are the most widely used.  Reaction turbines can be francis turbines or propeller turbines.  In a francis turbine, the water enters and flows radially, around the turbine shaft.

In a propeller turbine, the water flows axially to the shaft.

Francis turbines can be operated over a range of 40 to 105 percent of their rated discharge and 60 to 125 percent of their design head.  Francis turbines have a peak efficiency of 88 to 90 percent and can be mounted horizontally or vertically.  We have been in touch with Voith Hydro and have decided to use a horizontal francis turbine.


It was very difficult finding a turbine company that was willing to work with us and we would like to thank Voith Hydro for helping us with this project.  

WHAT WE KNOW

There have been studies done for the Greybull Valley irrigation district in the past.  These studies can be found at http://library.wrds.uwyo.edu .  I will be listing all pertinent information found on these studies here so that it can be used to build a project model.

There are restrictions that we must adhere to on this project.  A certain level must be maintained in the reservoirs (head).  Specifed flow rates must be maintained in the rivers after water is diverted to the reservoirs, the flow rates are in cubic feet per second (cfs).


Total irrigated acres: 80,000
Total storage capacity (all 3 reservoirs): 143,000 acre-ft
Irrigation season: April - October
Diversion to Upper: 900 cfs
Wood River diversion: 600 cfs
Sunshine creek: 250 cfs, 500 cfs with erosion protection
Avg diversion into upper (April -October): 53, 300, 601, 502, 307, 141, 59 cfs
Average diversion into lower: 67 472, 835, 674, 395, 187, 85 cfs
Roach Gulch Dam:
 Max gross head: 147 ft
 Avg. daily gross head: 100 ft April-July
                                    80 ft August
                                    65 ft September
                                    60 ft October
Upper Sunshine Dam:
 Max gross head: 150 ft
 Avg daily gross head: 122 ft all months


Lower Sunshine Dam:
 Max gross head: 170 ft
 Avg daily gross head: 139 ft all months


This information along with gaging station information in the Greybull and Wood rivers will be used to build a model representing likely fill and release procedures.  This model will determine if this project is economically feasible.

Environmental Impacts of Hydropower

The U.S. Department of Energy points out several negative impacts of hydropower.  Most of these impacts do not apply to the Lower Sunshine Reservoir Project due to the fact that the dam is off channel.  The one factor that does apply to this project is injury to fish.


The Department of Energy has developed four turbine designs to limit the damage to fish passing through the turbine.  One turbine design uses technology used in the food processing industry.  This design can be seen in the picture below.

I applaud the desire to be environmentally friendly, but I also see a potential for taking it too far.  We have to solve our energy problems, and yes, a few fish will be lost in the process.  I think these fish families would be proud that their loved ones gave their life in service to their country. 


http://www1.eere.energy.gov/windandhydro/hydro_rd.html

PEOPLE ARE WILLING TO PAY MORE FOR GREEN ENERGY

I know what your thinking but no, I haven't been drinking Al Gores' cool-aid.  A poll by Reuters ( http://www.reuters.com/article/2007/12/14/us-energy-idUSN1431302220071214) found that Americans are willing to pay 20% more for green energy. In fact, their  poll showed that 70% of over 2000 people surveyed around the world were willing to pay more for green energy.   


What does this mean to the world of Hydropower?  Plain and simple, it means money.  We are now able to develop projects that were not feasible at the rates paid for fossil fuel energy.  It means that the irrigation districts that build these projects will become self sufficient and be able to spend more money on their other projects.  As they improve their infrastructure, they will become more efficient which will allow more water to be used for the production of power and less for irrigation.


However, a recent ezine article (http://ezinearticles.com/?Will-Consumers-Pay-More-For-Green-Products-and-Technology?-Not-Yet&id=5320946) discussed the findings a little differently.  This author showed that even though people said they supported government subsidies, they were not willing to pay more than 5% more.


This issue is far from indisputable, but I believe that it is something that needs to be looked at.  A poll could be taken in the local area to determine if the customers who would use this new energy source are willing to pay more for green power.  A 5% increase means a $10,000 increase in annual profit for the Greybull Valley project, that is not something to be taken lightly.