Wind-power owners, developers and suppliers are preparing to soar under a new round of federal incentives. The news had 23,200 visitors—78% more than last year—blowing into the world’s largest conference on wind-generated electricity. On tap was February’s passage of the American Recovery and Reinvestment Act, which boosts production tax credits (PTCs) to reduce owners’ tax burden for the first 10 years of operation. Wind PTCs are extended two years, through Dec. 31, 2012. Developers also can claim an alternate investment tax credit (ITC) or Treasury Dept. grant to recoup 30% in the first year. Photo: Sarah Klose / ENR John
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.