According to the Energy Information Administration, Idaho, Washington, and Oregon in 2009 generated respectively 86%, 75%, and 66% of their electricity from renewables. Most of their power comes from conventional hydro power plants, with hydro providing Idaho 80% of its power; Washington 70%; and Oregon 58%. Wind and wood/wood waste provided nearly all the remainder.
In 2009 through first half of 2011, Washington and Oregon have had large wind power development. As ar result, it is likely that the proportion of electricity coming from renewable energy in 2011 will be even a bit higher in both Washington and Oregon.
Maine at 49.8% renewable energy was nearly a fourth state to get 50% of its power from renewables. Maine got 26% of its total power from hydro and 20.6% from wood/wood waste.
The lights stay on in these states, and power costs are very low in Idaho, Washington, and Oregon as nothing is cheaper than fully depreciated large hydro power plants.
Hydro also provides zero air pollution power--no mercury, nitrogen oxides, sulfur dioxides, mercury, arsenic, soot, lead. No heat trapping pollution. Hydro is good for human health and climate.
But, of course, the environmental impact of massive dam systems across great rivers is substantial.