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Ridgway Reservoir Micro-Hydro Project Loan Feasibility <br />Page 30 of 42 <br />Francis units {85 percent vetsus 92_5 percen#), meaning that the ener�y generafion could be a# least 7 <br />pezcent less �an that of tl�e recommended sol�ion. The cost �ade-off lies iu the cost of exca�ating and <br />inst�lling a draft tube far the Fraucis unit> which would nat be n�ecied for the Ossbetger uait. Should <br />scoar or related hydraulic issues vuiffi tbe e�ergency spillway outlet wodrs become problematic, �e <br />discharge from the �se unit would be much less ca�plicated and �m likely to ov,Et+coo�e <br />Reclama�on oir�ectia�ns, should they oocur_ <br />Table 1. General Turbine Uata <br />Pa�ameter lJnit 1 Unit 2 units <br />Twbine ty�pe Fbrizontal Francis i�aiz�tal Francis <br />Rated capacity 4.9 2.1 megawatts <br />Pea�lc ef%cier�cy 92.9 92.5 pe�c�t <br />I�mer diameter 49.6 31.3 inches <br />RatQd Disct�ar�ge 320 120 cfs <br />Gross tiead 200 200 feet <br />Maucimwn r�eet hc�ad 197 197 feet <br />hUnimum neat head 164 16�1 feet <br />Mini�ra flaw tirnugh wrbine 100 40 cfs <br />Maxim�sn fiaNr thro�gh turbine 370 1�10 cfs <br />Penstacks <br />The eus� ri��+er ox�tiet w+o�s is ca�rised af iwa pipes — a 6� inch stert pqae ihat pro�Rdes uri�on <br />8a��s, amd a 24�nch steel pipe ti�at �eets winter low-$ow �eu�ands_ 'The.�e pipes a�3e � inside a <br />cot�c�+ete t�mael imdesneath the dam At the aeress l�se, which is i�sed far P�pe �c�hon, Rerlaroatia� <br />ins�l�d a 5�nch ia�fiacation at the time of coushucti� that couid be used fo� a h��Opo�er faciliiy- <br />TSis t�ifia�estion w�ouid l��e dirErted flows to the west of ti�e access and ga�he houses_ <br />Thst optia� is � la�er a�ailabte. Therefore, ii is recommended ti�at tt�e b�fiuration v�snuid be capped <br />and a�* cosmeclia� �aild be ins�talled that directs flow to the east thnoag� a� 66-i�ch stee� pensto�ck <br />�o the p�w�ouse. "fhe pensto�k wo�nld be a sMel pipe desiganed to acc�odat�e the h�nsieat hydraulic <br />pa�essares geae�ated d�ing statt-up and shutdown of the hu�ines_ From the acress ha�se, the pipe would <br />be about 55 feet to the �w powerL�se_ llie pipe waild be buried_ <br />A uevv bifiurat�m w+auld be ffistalled in the 24i�ch liae sn�ci @inert low+er flows to t�e smaller of the two <br />t�mes_ Tbe p�k far tt�e smaller tmit would be a 24-i�tch steel pipe. Bo$i pmstodu aFOUid be <br />s�pocte�d �n the 1h�nc�► by an appropriate bedding mateiial of cnzsLed inck, and �fi b�locl�s wonid be <br />insta3l�d at pipe be�ds to absotb hyrdrautic loads_ <br />Bc� pen�tocks wrn�ld ha�*e �te ��atves in the penstock ups�tream of the hu�ine to isolate tltie turtrine <br />ci�uiag �imes of mainte�auoe, planued, a�d tmplantied outages. These vates a�auld be linked to the <br />existing slide �ate�s � th�e ric� outic� works to assure unint.enupted flaw to doa� �ers. <br />T he upper half of ea�ch dra8 tubes woaild be fat�ricated from steel, and inciuded in ti►e hu�r`generat� <br />eq�apm�ent P�ekage. T�e low�er half woutd be coastructed witlx reinfoir�+d c+�cmte. F.ach draft tuhe <br />wrouu�id be desigp�ed M pro�ide an esit velocity abont S feet per secaad to u�ffinrize or�all head losses_ As <br />noted aban��e, rt is p�annesi tl�at � discharges fi� the two tur�ines would be made to ihe stilling basin of <br />the �er�'S1a�llv►'83'_ Hist+n�icalty, that bss�iu has been used strirtty fa� i�e e�eS°' �Y- <br />Fo�arerhouse cii�char�es ha�,�e been �irected there to (a) minimize head l�ses and (b} redu�e �erall <br />Rid�+raY Hy�dro Fcasibility Summary Page 2 <br />