More reliable forecasts for water flows can reduce price of electricity

Science Daily: Brazil, Canada, China, the US, Russia, Norway, Japan, and Sweden are among the largest producers of hydroelectric power in the world. One problem for hydroelectric power companies is that the great variations in the river flow and the lack of long-term forecasts make it difficult for power companies to determine how much water in their dams should be saved or released.

But by scaling down information from global climate models and combining it with local measurement data, researchers at the Lund University School of Engineering (LTH) have developed a method that yields four-month forecasts that are twice as reliable as similar methods for run-off forecasts. The findings are published in an upcoming issue of Hydrology Research, and the model will be tested by StatKraft in Norway.

…."By predicting spring water resources as early as December-January, it is possible to steer electricity production so that water reservoirs are emptied more slowly, thus avoiding dramatic price hikes in subsequent seasons. The need to control water flows is all the greater because the value of water in the dams varies apace with the price of electricity," says Cintia Bertacchi Uvo, professor of water resources engineering at LTH.

…Today power companies use relatively accurate short-term run-off forecasts that are based on a combination of hydrological models and weather forecasts. But their long-term forecasts are less reliable. Their long-term run-off forecasts are calculated by running the hydrological models with two weather scenarios, one that yields low run-off and one that yields high run-off, which provides two extremes that the long-term planning can be based on.

"The problem with this method is that the run-off can wind up anywhere at all within this interval. A climate forecast like the one we have devised provides better probability for future run-off scenarios, which makes it possible to plan and prioritize different strategies," explains Kean Foster….

Olstappen dam, Nord-Fron and Sør-Fron, Norway, shot by Anders Einar Hilden, Wikimedia Commons