20276 SW Lela Lane

Beaverton, Oregon 97006

(503) 356-8302

lsheldon2@frontier.com

 

May 16, 2011

Judge James A. Redden

1000 SW Third

Suite 1527

Portland, Oregon 97204

 

Dear Judge Redden:

            Last week I sent a letter dated May 7, 2011, requesting an appointment with you concerning hydropower.  I understand that even though I have no connection with any ongoing litigation, you are unable to meet with me for legal reasons.  However, I am informed I am at liberty to send you a letter addressing the matters I wished to discuss in person.

            If you remember my letter and personal resume of last week, I am a professional engineer who has worked in hydropower for the past 42 years.  During all that time, there has been a solution to the Columbia River downstream fish mortality problem that has been ignored or brushed aside for reasons that I and other fellow engineers simply can not understand.  I even published this remedy internationally, in exacting detail, about 30 years ago, but to no avail.  Since we can not meet and I have no knowledge of your exact familiarity with this technology, I will start with the basics, but be as brief as possible.

            The hydraulic turbines we are considering are vertically shafted Kaplans.  These machines have propeller like runners (the rotating element), which are surrounded by wicket gates that open and close to control the flow of water to the runner and thereby control the power produced.  These are called Kaplan type, after the inventor Dr. Viktor Kaplan, because the pitch angle of the propeller blades is adjustable.  This feature allows the turbine to generate at a high efficiency over a wider range of heads and flows than a fixed blade runner.  Specifically, as the wicket gates open at a given head, or as the head increases at a given gate opening, the flow rate entering the runner blades increases.  We say the velocity vector is getting steeper.  Correspondingly, the blades should go to a steeper pitch angle to meet this steeper velocity vector of the incoming flow.  There is an analogy to the angle of attack of an airplane wing.  The efficiency and performance of Kaplan turbines is extremely sensitive to the blades being at the optimum pitch angle for the amount of wicket gate opening and head.  As I believe you are aware, the survivability of downstream migrating fish is a function of the efficiency of the turbine.   

            This optimum blade angle is determined in the field by a relative efficiency test known as an “index test.”  The term index means simply that the flow rate is measured by indexing it against another parameter rather than measuring it directly.  These tests are fairly inexpensive to conduct, involving 3 or 4 persons for about 2 days.  A skilled test engineer can actually increase the efficiency of the turbine even while testing it.

            Once the field data is reduced, the new optimum blade to gate to head relation can be programmed into a normal governor so that the turbine operates at its optimum efficiency.  The few controlled fish mortality studies done on specifically indexed Kaplan turbines have shown survivability of about 98%.  This, of course, was also with governors from commercial vendors that met industry standards of controlling the pitch angle of the blades to + 0.1 degrees.

            Ideally, an index test should be done about once every four years on every Kaplan.  Indexing every four years or so is because the optimum blade to gate to head relation changes with the wear and tear on an operating unit.  The reason to do it on every Kaplan is that all Kaplans, even those purchased under the same contract, are all different.  A noted example is the original 16 turbines for The Dalles dam, purchased together under a single contact.  When tested with current meters (not indexed) in the 1960’s their peak efficiencies were found to vary by 7% and the power at which peak efficiency occurred varied over a range of 10 megawatts.

            Now, what is the situation on the Columbia and Snake Rivers with the Corps of Engineers’ Kaplan turbines?  The vast majority of the turbines in the Corps’ inventory are never indexed during their entire service life.  At best, only one of a family are tested and usually only at one head.  It is assumed that all the other turbines in that family are the same and will wear the same in operation.  Second, even when there is an index test, there is no procedure to verify the optimum blade to gate to head relation is ever programmed into the governor.  Even if that is done, most of the Corps governors were not procured from normal equipment vendors and can not meet industry standards.  In fact, to prevent these governors from “hunting” individual projects have increased the dead band on blade pitch control to +1.0%.  This alone causes a loss of efficiency of about 0.7%.

            Much of the test data on fish mortality we have today was obtained from Kaplan turbines without any regard as to their performance profiles, let alone whether they were ever indexed or not.  This lack of fish testing on uniformly optimized Kaplan turbines is what has given such variability to the results of fish studies.

            In summary, if we made a concentrated effort to index our Kaplan turbines, program the governors with the proper blade to gate to head data, and tightened our governor deadbands to industry standards, we would have downstream migrant survivability higher than that by spill or downstream bypass handling facilities.  We would also increase our energy production.  A study done by a BPA contractor about 18 years ago concluded that, “Optimizing hydropower generation provides the lowest cost firm energy available from any resource.”

 

Sincerely,

 

 

 

Lee H. Sheldon, P.E.