The URL can be used to link to this page

Home My WebLink AboutCordova Regional Hydro Resource Assessment Apr 2017Memorandum To: Craig Kuntz, Cordova Electric Cooperative From: Daniel Hertrich Subject: Cordova Regional Hydro Resource Assessment Date: April 13, 2017 Intrndtic, inn � ALAS K A � ENERGY AUTHORITY Cordova Electric Cooperative (CEC) recently completed a feasibility assessment of the Crater Lake resource and requested that AEA review of the study. In the course of reviewing the Crater Lake feasibility study AEA performed a more comprehensive desktop level analysis of Cordova's existing hydro generation and other regional hydro resources. This memo presents the evaluation of the existing electric energy generation configuration in Cordova, AK and looks at the potential benefits of both the Crater Lake resource and the Raging Creek resource. Other resources not examined include adding storage to Power Creek (due to previously cited geotech concerns), Rogue Creek, Beartrail Creek, Heney Creek, and an unnamed creek near Scott Lake and various others and/or pump storage projects although the hydrology analysis presented here enables preliminary evaluation of those projects. CEC currently operates two hydroelectric and one diesel generation stations. The hydroelectric projects are Power Creek, a 6 MW run of river project, and Humpback Creek, a 1.2 MW run of river project. Even during the summer there are times when the demand exceeds the peak hydro capacity and diesel generation is required. Through the remainder of the year, and particularly in the late winter, significantly more diesel generation is required because the hydro projects have reduced power output due to low flow. Existing System configuration The table below shows the average monthly power generated along with the peak demand (from PCE data): Month Avg Diesel Power, kW Avg Hydro Power, kW Avg Total Demand, kW Avg Peak Demand, kW 1 1,579 888 2,467 3,653 2 1,487 747 2,234 3,407 3 2,100 469 2,570 3,951 4 2,011 649 2,660 3,734 5 601 2,312 2,913 4,272 6 373 3,310 3,683 5,978 7 533 4,000 4,533 6,541 8 814 3,501 4,315 6,453 9 759 2,193 2,951 4,761 10 638 1,686 2,323 3,367 11 1,201 1,207 2,408 3,451 12 1,621 921 2,541 3,520 Average 1,143 1,823 2,967 813 west Northern Lights Boulevard Anchorage, Alaska 99503 T 907.771.3000 Toll Free (Alaska Only) 888.300.B534 F 907.771.3044 Alaska Energy Authority Cordova Regional Hydro Resource Assessment Annual energy generation by resource: Power Cost Equalization Data Diesel kWh Hydro kWh Total kWh Year Generated Generated Generated 2001 11,333,549 868,128 12,201, 677 2002 13,882,408 10,675,290 24,557,698 2003 8,398,479 15,515,849 23,914,328 2004 7,418,138 16,622,683 24,040,821 2005 6,056,449 19,400,702 25,457,151 2006 11,813,931 13,470,088 25,284,019 2007 13,259,268 13,627,195 26,886,463 2008 10,827,607 14,830,533 25,658,140 2009 10,921,141 15,062,381 25,983,522 2010 9,774,568 17,740,374 27,514,942 2011 9,155,217 16,759,928 25,915,145 2012 10,967,881 17,021,008 27,988,889 2013 9,364,225 19,482,939 28,847,164 2014 7,747,532 19,481,409 27,228,941 2015 7,884,868 21,013,732 28,898,600 2016 5,733,054 19,410,370 25,143,424 Average 9,658,645 15,686,413 25,345,058 Existing hydroelectric project configurations: Humpback Creek Project Description Value Unit Hydraulic Capacity, cfs 95 cfs Spill Elevation 188 ft Turbine Elevation 0 ft Static Head 188 ft Friction Loss 7.22 ft Net Efficiency 86% Net Power 1255 kW Power Creek Project Description Value Hydraulic Capacity, cfs Spill Elevation Turbine Elevation Static Head Friction Loss Net Efficiency Net Power Energy Demand and Generation by Resource Humpback Creek and Power Creek Generation Evaluation: Humpback Creek Annual Energy Generation, kWh 320 283 0 283 2.58 79% 6001 Unit cfs ft ft ft ft kW Month 2012 2013 2014 2015 2016 Average 1 79,530 230,192 365,290 307,506 309,368 258,377 2 165,269 178,878 72,706 197,951 285,027 179,966 3 35,733 54,816 66,577 162,988 230,067 110,036 4 232,680 59,942 105,963 247,495 420,553 213,327 5 571,073 524,232 262,595 378,507 546,957 456,673 6 529,777 712,795 299,053 368,872 353,139 452,727 7 552,595 457,924 245,471 262,251 290,584 361,765 8 469,704 394,095 508,541 193,980 559,426 425,149 9 446,024 316,522 372,111 255,821 336,241 345,344 10 284,713 338,531 258,668 369,795 78,348 266,011 11 71,358 156,680 257,077 216,153 234,323 187,118 12 71,772 83,869 112,350 86,575 88,642 Total 3,512,240 3,510,489 2,816,066 3,075,684 3,732,624 3,345,135 Total PCE Hydro 17,021,008 19,482,939 19,481,409 21,013,732 19,410,370 19,281,892 Percent of Total 21% 18% 14% 15% 19% 17% Power Creek 13,508,768 15,972,450 16,665,343 17,938,048 15,677,746 15,952,471 April 13, 2017 Page 2 of 8 Alaska Energy Authority Cordova Regional Hydro Resource Assessment Hydrology Cordova Regional Stream Gauge Data Sets Drainage Number Station Name Dec Lat Dec Long Area, sq mi HUC code 15195000 DICK C NR CORDOVA AK 60.3416822 -144.3047573 7.9 19010402 15215900 GLACIER R TRIB NR CORDOVA AK 60.5327973 -145.3806148 2.2 19020104 15215990 NICOLET C NR CORDOVA AK 60.5186253 -145.7917173 0.7 19020201 15215992 HENEY C AT CANYON MOUTH NR CORDOVA AK 60.52335006 -145.7633808 1.53 19020201 15216000 POWER C NR CORDOVA AK 60.58667537 -145.620022 20.6 19020104 15216003 MIDDLE ARM EYAK LK TR NR CORDOVA AK 60.5575101 -145.6308655 2.9 19020104 15216008 MURCHISON C NR CORDOVA AK 60.5364038 -145.716152 0.37 19020104 15216100 HUMPBACK C NR CORDOVA AK 60.6108405 -145.6786214 4.37 19020201 15219000 WF OLSEN BAY C NR CORDOVA AK 60.7608659 -146.174225 4.9 19020201 Year 15195000 15215900 1 15215990 15215992 15216000 1 15216003 15216008 15216100 1 15219000 1947 130 1948 366 1949 365 1950 365 1951 365 1952 366 1953 365 1954 365 1955 365 1956 366 1957 365 1958 365 1959 365 1960 366 1961 365 1962 365 1963 365 1964 366 122 1965 365 365 1966 365 365 1967 365 365 1968 366 366 1969 365 365 1970 214 365 365 1971 365 365 365 1972 366 366 366 1973 365 365 92 365 1974 365 365 365 365 1975 365 365 273 365 1976 366 366 366 1977 365 365 365 1978 365 365 365 1979 365 365 365 1980 366 366 366 1981 273 365 33 1982 365 1983 365 1984 366 1985 365 1986 365 1987 365 1988 366 1989 365 1990 365 1991 92 365 92 92 1992 366 366 366 366 1993 273 365 273 273 1994 365 1995 273 1999 125 2000 366 2001 365 2002 365 2003 365 2004 366 2005 365 2006 365 2007 365 2008 366 2009 365 2010 365 2011 180 136 2012 366 2013 365 2014 365 2015 365 2016 351 2017 18 Total 4140 1 2010 1 4279 1 731 1 17570 1 731 1 731 1 730 1 5999 April 13, 2017 Page 3 of 8 Alaska Energy Authority Cordova Regional Hydro Resource Assessment Median Unit Discharge, cfs / sq mi 15195000 15215900 15215990 15215992 15216000 15216003 15216008 15216100 15219000 Month DICK C NR CORDOVAAK GLACIER R TRIB NRCORDOVA AK NICOLET C NR CORDOVAAK HEN EY CAT CANYON MOUTH NR CORDOVAAK POWER C NR CORDOVAAK MIDDLEARM EYAK LK TR NR CORDOVAAK MURCHISON C NR CORDOVAAK HUMPBACK C NR CORDOVAAK WF OLSEN BAY C NR CORDOVA AK 1 2.0 3.1 2.3 2.6 2.5 2.8 0.7 1.5 1.0 2 1.5 2.3 2.1 1.6 2.2 2.6 1.4 0.8 0.7 3 1.4 1.0 2.6 3.3 1.8 3.81 1.4 0.6 0.6 4 5.1 3.5 7.4 9.8 2.1 7.6 1.8 3.4 2.7 5 19.6 9.1 10.8 25.2 9.6 19.8 13.8 11.7 9.4 6 23.2 10.0 2.1 23.5 20.4 24.5 26.2 16.0 11.6 7 18.4 7.5 1.7 15.0 23.0 16.0 10.8 11.2 8.2 81 12.0 8.2 2.1 12.7 20.1 16.4 3.9 6.4 5.1 9 12.2 8.4 5.5 7.5 17.5 16.0 3.8 15.9 5.0 10 18.5 5.5 9.6 14.7 11.7 10.0 4.1 10.5 6.1 11 5.4 2.5 5.4 7.5 5.1 7.4 2.7 3.1 2.7 12 3.2 1.2 2.9 3.0 3.3 3.2 1.4 2.6 1.5 Average Unit Discharge, cfs / sq mi 15195000 15215900 15215990 15215992 15216000 15216003 15216008 15216100 15219000 HENEY CAT CANYON MIDDLEARM WF OLSEN BAY Month DICK C NR GLACIER R TRIB NICOLET C NR MOUTH NR POWER C NR EYAK LK TR NR MURCHISON C NR HUMPBACK C NR C NR CORDOVA CORDOVA AK NR CORDOVA AK CORDOVAAK CORDOVAAK CORDOVAAK CORDOVAAK CORDOVA AK CORDOVAAK AK 1 11.0 5.4 12.1 5.1 3.6 3.3 3.2 1.6 3.3 2 10.0 3.9 10.6 6.9 3.1 7.0 1.7 0.9 2.9 31 4.6 2.3 7.51 6.2 2.3 5.2 6.9 0.61 1.9 4 9.9 4.5 14.9 9.9 2.9 8.3 4.4 3.8 3.6 5 24.2 10.0 14.2 26.4 10.4 21.1 19.2 13.3 10.2 6 25.8 11.1 5.7 25.0 22.0 24.9 27.2 16.6 12.5 7 22.7 10.0 6.9 19.8 25.6 17.6 16.1 14.2 9.3 8 22.8 12.8 11.5 27.2 24.5 29.0 17.5 8.2 7.3 9 24.0 15.1 15.4 17.1 24.6 23.6 22.1 19.2 10.2 10 28.9 8.3 20.9 19.8 16.9 13.7 7.9 14.4 10.1 11 16.0 4.3 17.6 11.9 8.1 11.1 5.2 8.3 6.2 12 7.2 2.2 14.7 6.4 4.5 4.4 4.3 4.2 2.8 25.0 Median Unit Dis rge, cfs/sq mi 20.0 GLACIER R TRIB NR CORDOVA A POWER C NR CORDOVA AK WF OLSEN BAY C NR CORDOV AK 15.0 Selected Regional average 10.0 5.0 �� Energy analysis used sites highlighted in green (also sites shown in chart above). April 13, 2017 Page 4 of 8 Alaska Energy Authority Cordova Regional Hydro Resource Assessment Project Configuration Analysis The four projects analyzed using the hydrology data above are Humpback Creek Project, Power Creek Project, Crater Lake (storage) Project, and Raging Creek Project. The Crater Lake Project performance analysis uses the average unit discharge because it is a storage project. The remaining three use the median unit discharge because they are run of river projects. The analysis used monthly medians/averages only. A more detailed multiyear daily or better analysis should be performed. Below shows the two new project configurations. Crater Lake Project Raging Creek Project Description Value Unit Description Value Unit Hydraulic Capacity, cfs 6 cfs Hydraulic Capacity, cfs 95 cfs Spill Elevation 1500 ft Spill Elevation 850 ft Turbine Elevation 100 ft Turbine Elevation 100 ft Static Head 1400 ft Static Head 750 ft Friction Loss 48.45 ft Friction Loss 21.09 ft Net Efficiency 85% Net Efficiency 86% Net Power 580 kW Net Power 5009 kW EnerRv Generation Analysis The monthly average median and average unit discharge of the selected USGS gauge data is presented below. For Power Creek only the Power Creek USGS site was used. Unit Discharge (cfs/sq mi) Power Creek Unit Discharge (cfs/sq mi) Month Median (run of river) Average (storage) Median 1 2.2 4.1 2.5 2 1.7 3.3 2.2 3 1.2 2.2 1.8 4 2.8 3.7 2.1 5 9.3 10.2 9.6 6 14.0 15.2 20.4 7 12.9 15.0 23.0 8 11.1 14.9 20.1 9 10.3 16.7 17.5 10 7.8 11.8 11.7 11 3.4 6.2 5.1 12 2.0 3.2 3.3 Average 6.6 8.9 9.9 April 13, 2017 Page 5 of 8 C a) E cn rn a) to Q U 3 O N a) m Y rn m ZY r" N OIn O� W m m W m t Ln r, Ln N oo a oo iD oo Ln of ` oo m ,o o0 _ LO M 1l N N V V O M':T W 0 00 oo O Ln m O O N lD Ol r-I N N N rr w LO Vl m 00 01 LD 1` '1O lzl O lD N ry.1 N m m m m N c-I m N LU 01 M M r-1 LO N 1� n ri 1, Ln lD ;q, N N 00 ill O O O Vl Ol I�T N M ai 3 m n ar-i m m 0 W N m It 00 6 o O_ Y Y w i Ln 1l ri m o of ci m Ln LD ci o0 0 U a) 1, m Ol cl 'ZT O N CO "J "I 1" M N to w "1 ci N 1, ri 0 CO 00 LO N c-1 Ln L r6 OC '� 0 u 1, -zl- 00 m y v m o V 00 w r, 00 001,Nm1,w01,1100viD IZT o It Ln lzz LD oo ci o 00 m r , o al s MT r,Vl w ill l0 N m lP N O 1� r,w oo LD -zt n r-I ri ri ri �* Ln N lD N N N N M M M M N ri N 0 W Y N L 1, 7 m Ln .-i Ln Ol Vl l0 1, n O ci rn LO o m m N N r, m n rn ci ci N V V-zT a M ri 3 o � O_ Y y r, :t m Ln ci Ln Ol Ln LD 1- n O Ln rp ci al l0 O Ol m N N 1" m 1, Ol N L fo "1 O o "q NIt M r-I 0 ♦✓ � u � y U � u V 00 N Ln O W O Ln Ln O N 1, N N l0 O oo oo Ln 1, Ol O Ln N r� m m 00 1, M I, W N O 00 00 0) m 1l O T M 00 00 M LO Lrl r- N N 0 Olzz Lrl '0 N Ql lD oo En 41 C r-I M Ln Ln � 4 M rr-1 N rrl i W Y N m lO m lD oo M Ol Ln lD 1- M Ln 4/ aNr�-I Ln I� lD L11 r� -I-I ri GJ d Y U O I- Ln Ni O1 i q m Ln 00 m � w Ln "I N CO.._ G U 3 x so I^ L N 1, o M Ln 0 0 0 0 0 0 0 lD Ln m 00 U) Ln 0 0 0 o m N n r-I M M ri M 00 O O O o Cl W N W Y al N O1 Ol 1, O V�t O 00 V m qt S T w Ln M M 00 N LD lD N 1- M M'T w m a Ln Ln M V qT M r-I M 00 00 r 7 7 a V ff c-I N LLI N oLncil,000000mvci 0 0l 1l r, r, 0 0 0 0 1, m 0 1� 'T 0 0 0 o N 00 N ro o O_ Y m lD D D LO 'T r-I r-I Y y 00 N lD c-I LO lD lD r-I M 00 Ol 7 M U LM azd- M � a) 3m't M M N 1-1 L d @ 3 u o a � u .-I N m zt Ln LO 1, 00 Ol O E `ci-I `N-I Y C O L^ W 4+ C > C a) Ln � v= O O U 1z a) L � U � ?i v a) L o v Q L -le C7 DA O ,- m L +- M U ra U i- L 0 3 C O r0 a \ G� O ~ 4- C * r-I L i- Q) 3 O Lr) 0 a) Lll rp 1]A M N Y ro a) ro U 3: 'a u t CCO QC C C Ln L a) L a) a) Q (6 4- C 4J Ln O > 2 'O a) Vf a) L 4-1 f0 > O L O 4' a- f6 Ln U N Q Vf Q i i U O V L N O Q N U cu cv U L +' L a) C O O i O -C a) d a) Q a) � v H � N N > a) O 3 C C `" O `~ rn 3 O L C > 3 L L 00 Q n cc +� C L 4- a) a) L C H0 v UO E co O a) 0) m CL Alaska Energy Authority Cordova Regional Hydro Resource Assessment System Modeling The modeling of the integration of Raging Creek evaluates its performance against the current average amount of diesel generation. A more detailed multiyear daily model would be appropriate to better evaluate the project and particularly relating to peak demand and to establish required storage if it is feasible. Load growth factors should also be applied in the analysis. Month Average of CEC Diesel kWh Generated Raging Creek Energy, Useful kWh Remaining Diesel Generation or Energy Storage Required, kWh Raging Creek, Equivalent Storage Volume reqd, acre-ft 1 1,174,975 686,579 488,396 747 2 1,034,687 503,225 531,461 813 3 1,562,669 357,850 1,204,819 1844 4 1,447,849 832,651 615,198 942 5 447,389 447,389 0 0 6 268,507 268,507 0 0 7 396,807 396,807 0 0 8 605,569 605,569 0 0 9 546,307 546,307 0 0 10 474,396 474,396 1 0 0 11 864,759 864,759 0 0 12 1,205,736 620,379 585,357 896 Total 10,029,649 6,604,418 3,425,232 5,242 In summary, this analysis concludes the Raging Creek project could displace approximately 6.6 GWh of diesel generation. The Crater Lake project energy (2.2 GWh) would be nearly fully utilized. If that project is pursued then modeling with the multiyear daily record of aggregated USGS data would be required to establish the storage requirements which are likely to very minimal for this project. Summary A significant amount of additional work would be required to say whether development of the Raging Creek resource should be pursued. AEA notes the project is very similar to the Hiilangaay (formerly named Reynolds Creek) Hydro being constructed on Prince of Wales Island for about $20 million. At first glance, the Raging Creek project appears to be a better resource than Crater Lake and AEA recommends Cordova Electric continue to look at it as a potential generation resource in addition to any other alternatives available. April 13, 2017 Page 7 of 8 Alaska Energy Authority Cordova Regional Hydro Resource Assessment Raging Creek Project Location April 13, 2017 Page 8 of 8