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Alternative Analysis <br /> CH2MHi11 and Northern Water performed alternative analyses of both potential powerhouse locations as <br /> well as turbine sizing. The following three powerhouse locations were evaluated: <br /> • Tunnel outlet. This option placed the powerhouse directly at the mouth of the tunnel and was <br /> initially considered the preferred option. A single 54-inch diameter penstock connecting to the <br /> outlet would have been included. However, due to concerns by Reclamation regarding potential <br /> future work at Granby Dam and the impacts that work might have on the powerhouse, this option <br /> was removed from consideration. <br /> • Downstream hillside. This option would place the powerhouse approximately 300 feet <br /> downstream of the tunnel mouth. A new wye would be installed within the tunnel and a 36-inch <br /> pipeline would be extended from that point. The main outlet valve would continue to remain <br /> within the tunnel. Due to slope stability concerns with the hillside behind the powerhouse, this <br /> option was removed from consideration. <br /> • Streamside. This option is similar to the previous option except the powerhouse would be <br /> located along the bank of the outlet channel and would be approximately 200 feet from the <br /> tunnel mouth. This is the preferred option upon which the design is being performed. <br /> An analysis was also made for optimal turbine sizing. The goal was to cover the flow range from 20 cfs <br /> to 76 cfs. Scenarios analyzed included a single Francis turbine covering the 20 cfs to 45 cfs range, a <br /> single Turgo unit covering the 20 to 76 cfs range, and a two-Francis unit configuration covering the full <br /> 20 to 76 cfs range. The optimal configuration considering cost and revenue was the two-Francis unit <br /> configuration. Several specific turbine runner options have also been considered in order to optimize the <br /> amount of power produced from the project. <br /> Project Components <br /> The project will include these components: <br /> • Connection to the existing outlet within the Granby outlet tunnel. <br /> • 500 feet of 36-inch diameter penstock supported within the existing tunnel. <br /> • 200 feet of additional penstock outside the tunnel. <br /> • Two 600 kilowatt Francis turbines with associated generators and electrical gear, anticipated to <br /> be provided by Gilkes, the turbine supplier for Carter Hydro. <br /> • A 70 foot by 26 foot power house located along the bank of the existing tunnel tailrace. <br /> • 1,000 feet of overhead powerline and associated switchgear to connect to Mountain Parks <br /> Electric Inc. (MPEI). <br /> Figure 4 shows the overall project layout. Figure 5 and 6 provide a layout of the hydro facility in plan <br /> and profile view, respectively. <br /> 5 <br /> • <br />