The biggest wind-energy meeting ever held in the U.S. opened today in Portland, Ore. Industry-watchers say the large turnout — more than 1,500 people have registered for the three-day conference — is a good sign for wind energy in general and for the role of the Pacific Northwest in the wind market in particular. Oregon doesn’t have the best wind resources in the country, but it does have a strong base of environmentally minded consumers who are willing to pay a little more for clean energy and are driving a slow but steady local energy revolution. Just under 2 percent of Portland General Electric’s residential customers opt for renewable energy, as do 1.7 percent of Pacific Power’s residential customers. Although those numbers sound small, they are far larger than most states’ renewable-energy customer base. Since 1998, new Northwest wind projects have added enough power to the grid to serve 100,000 homes.