"a delicate balance"

PORTLAND, Ore. -- The manager of most of the electricity in the Pacific Northwest is running such a surplus of power from hydroelectric dams that it put wind farms on notice Friday that they may be shut down as early as this weekend.

The Bonneville Power Administration has more than enough electricity during a cold, wet spring that has created a big surge in river flows where hydroelectric dams are located. The agency responded by announcing its intentions to curtail wind power until the grid has more capacity, in a move likely to cost the industry millions of dollars.

The decision reflects an overlooked issue amid the push to add wind farms around the country: The capacity of power grids has not kept pace