This paper provides an estimate of the power-system value of water that remains in the river from conserved irrigation diversions, both in terms of energy gained and increased revenues, at various locations in the Columbia River Basin.
It should be noted that for certain watersheds in the region, conserved irrigation water may more likely be utilized by other water users and, therefore, not pass through the hydroelectric system. For these areas, there is no additional energy generated or increased revenue and thus no power-system benefit. For conserved diversions that stay in the system, however, for each thousand acre-feet of water that passes through Grand Coulee and all downstream dams generates 1,026 megawatt-hours of energy over the irrigation season. The same volume of water left in the system in the upper Salmon, the Walla Walla and the Deschutes areas generates 216, 147, and 46 megawatt-hours, respectively. Average revenues gained from conserved irrigation diversions at the sites listed above are roughly $57, $12, $8 and $3 per acre-foot, respectively (based on an average electricity price of $55 per megawatt-hour).
The Regional Technical Forum has developed savings estimates for measures to reduce water usage for irrigation. These measures will not only save electricity but also water that in many cases will stay in the river and produce additional hydroelectric generation. The added power system value of water that stays in the system could be used by the RTF and others to more fully capture the benefits of these conservation measures. The attached report describes the methods used to assess the added power system benefit and provides results for various locations in the basin both in terms of gained energy and revenue.
For questions about the paper or analysis, contact John Fazio.