How climate change will affect timing, volume of river flows and hydropower

Climate change is likely to bring warmer, wetter winters, earlier snowmelt runoff, and longer, drier summers to the Pacific Northwest of the U.S., says the Northwest Power and Conservation Council.

How climate change will affect timing, volume of river flows and hydropower

Climate change is likely to bring warmer, wetter winters, earlier snowmelt runoff, and longer, drier summers to the Pacific Northwest of the U.S., says the Northwest Power and Conservation Council.

Scientists from the Pacific Northwest National Laboratory told NWPCC at a recent meeting that “hydropower dam operators need to be ready for the change.” They were citing the results of an international study by researchers for the European Union and U.S. Department of Energy, who have been studying the possible responses of water-dependent power systems like that in the Columbia River Basin to climate change.

Preliminary analyses of climate change effects on temperature and river flows indicate that the critical period, in terms of planning resources to maintain power supply adequacy, will change from winter to summer within the next 20 years. Warmer winter temperatures reduce demand for electricity at the same time that more water (and hydroelectric generating capacity) is in the river, potentially eliminating some shortfall possibilities. Conversely, summer power demand is expected to increase with higher temperatures and increased cooling demand while river flows are expected to be lower, primarily due to a smaller mountain snow pack, which will increase the likelihood of a power shortfall.

With the expectation that annual spring runoff will move earlier in the year, dam operations will have to be adjusted to continue to protect against flooding and to help fish migrating in the Columbia River in the warmer spring and summer, said John Fazio, a systems analyst for NWPCC.

NWPCC will consider climate change in its planning and will use the data from this study for its Northwest Power Plan, which assesses power demand 20 years into the future and assigns low-cost, low-carbon generating resources, as well as energy efficiency improvements and demand response, to meet the anticipated demand.