You may have heard or read about a report – released earlier this year by the Department of Interior – that warns of diminishing water supplies in the western and southwestern U.S.
Billed as the first comprehensive and coordinated assessment of climate change and its effect on eight major river basins in the U.S., the report projects an 8 percent to 20 percent decrease in the annual flows of the Colorado, Rio Grande and San Joaquin river basins.
Although the report confirmed what most climate change experts already knew, it provides a starting point for the development of sustainable water resource management in the U.S.
The effect on hydropower generation could be significant. The report underscores the importance of developing water resource management techniques designed to mitigate the effects of climate change on hydropower production.
Hydropower producers in the Northwest rely heavily on runoff from melting snowpack to meet demand throughout the year. Climate change, however, is expected to reduce snowpack as experts forecast a transition from a snowfall hydrology to a rainfall hydrology.
As hydropower producers lose the ability to store energy as snow, their ability to store the added rainfall in reservoirs is limited. At some point, the added rainfall must be released as the reservoirs fill.
This looming scenario is sure to create more conflicts between hydropower producers and wind power producers as grid operators may be forced to curtail wind power amid temporary gluts of low-cost hydropower.
A responsible choice
In May, the Bonneville Power Administration, a major power provider in the Pacific Northwest, ordered many of the region’s wind power producers to shut down generation for several hours a day to make room on the grid for a surplus of hydropower created by heavy rains and significant snowpack melt.
The order came as the U.S. Army Corps of Engineers increased river flows to maintain space in upstream reservoirs for further runoff from the largest Northwest snowpack since 1997.
BPA had two choices: It could dial down generation from its hydropower plants and spill the excess water over dams, threatening endangered salmon; or, it could use the surplus water to generate clean, reliable, low-cost electricity.
BPA said it could not simply spill the large amounts of water behind its dams due to laws protecting salmon. Diverting the water through spillways would have raised dissolved gases in the water to deadly levels for salmon passing through the spillway, BPA said. Instead, the surplus water supplies were used to generate hydropower for customers in the Pacific Northwest.
BPA made the right and responsible choice for its customers.
Using hydropower instead of wind power to balance load made the most sense because of the higher cost of wind power, the intermittent nature of wind power and an obligation to abide by laws designed to protect endangered salmon. What’s more, hydropower is a more predictable and dependable source of generation.
It’s time that wind power producers bear more responsibility for maintaining a reliable grid. To achieve this, they should consider negotiating a curtailment clause into their contracts to avoid future conflicts.
The wind power industry said BPA’s decision to suppress nearly 100,000 MW of wind power in favor of its own hydropower generation cost wind power producers millions of dollars in broken contracts and lost tax credits. The industry has threatened to sue to recover the lost revenues.
Right now, though, the wind power producers are more interested in defeating the precedent set by BPA, which could diminish the strength of their contracts to provide power.
Much is at stake. The outcome could affect the level of renewable energy development in the U.S., especially in the Northwest.
— Russell Ray is Senior Editor of Hydro Review magazine and Chairman of the HydroVision International conference program.