Conservation will meet almost 60% of added energy demand over the next five years in the Pacific Northwest if a draft plan released on Sept. 4 by the Northwest Power and Conservation Council is adopted. Over the next 20 years, that figures jumps to 85%. The council devises a new plan every five years to guide power development in Montana, Idaho, Washington and Oregon. Each state’s governor appoints two members. Electricity demand will grow 2,058 MW between 2010 and 2014, says the plan. It suggests that 1,200 MW could come from conservation measures such as smart-grid energy management, power-storage improvements,
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.