Electrical Power for Valdez and the Copper River Basin-1981

As footnoted, the Alaska Power Administration adopted future powerdemand estimates front CVEA's 1976 power requirements study. The studyincluded estimates of demands through 1991; APA made a rough extension tothe year 2000, assuming a 6 percent rate of increase.Also footnoted is the actual performance of the utility from thebeginning year of the APA forecast to 1979. This projection was fairlyaccurate for 1976 and 1977 but diverged considerably in the years 1978and 1979. These later years represent a lull between the wind-down fromthe pipeline activity and the initiation of the ALPETCO refinery. TheRetherford Associates projection is too recent to test against historicaldata, however, a corresponding forecast made by Retherford in 1976 performedinversely to that of APA, with the greater inaccuracies appearingin the earlier years. Although the current Retherford projection willprobably out-perform the earlier APA forecast, it is ill-suited for theexpected high activity years of the early 1980's. The load forecastwhich is considered to be most accurate and was adopted for this study isAPA's 1980 estimate. Much too recent to test against historical data,this projection represents the best compromise between the other two, andincorporates the most current information available. This extrapolationis essentially a variation of Retherford with the earlier year adjustedto account for ALPETCO construction and subsequent maintenance, and alater period of reduced growth rates in the face of energy conservation.A graphic comparison of the various forecasts is shown on Figure B-4.Annual load factors are expected to remain in the 50 percent range.The incentive for the Valdez-Copper Valley community to avoid dieselgeneration is better understood in view of the fact that 1981 costs forthe system are expected to reach 114 mills per kWh. New hydro construction,with its high capital investment, does not appear resoundinglypreferred to diesel at this time. However, developments since 1973,including the abrupt price adjustments of 1979, cast considerable doubton the standard analysis based on fixed relative costs.Figures B-S through B-10 on the following pages portray how thesystem would look for the minimum, average, and peak weeks in 1990 and1995 with the addition of the PRT and Allison hydropower. The loadshapes are based on actual data for the combined systems of Glennallenand Valdez.The various shaded areas on the graphs represent the amount of firmenergy available during the respective weeks. It does not represent theactual ,mode in which it will operate. For example, Figure B-5 showsAllison hydro operating in a base mode with a continuous output of about4 megawatts. In reality, it may be used primarily for peaking.With the proper interfacing of the PRT with the Solomon and Allisonhydroelectric projects, it may be possible to increase the winter outputfrom the hydropower projects. This could be accomplished by increasedutilization of the PRT during periods of less demand. However, this wasnot taken into account for the graphic representations.B-11