More than any other European nation, the U.K. is pinning its hopes for a low-carbon-electricity future on offshore wind power. It already has more offshore generation than any other nation, at over 1,000 MW. But with construction costs posing the major hurdle to reach the U.K.’s goal of generating 12,000 MW by 2020, the quest is on for the best foundations in ever-deeper waters. Because of supply bottlenecks and other factors, the real construction cost of offshore wind farms has risen 20% since the first commercial schemes were built seven years ago, says Rob Hastings, head of marine resources at
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.