If you've never seen offshore wind turbines, it's hard to appreciate their scale. Blades can exceed 85 yards in length, their tips sweeping arcs almost 180 yards in diameter. They twirl atop towers a football field high and can produce enough electricity to power more than 1,500 homes.
Now imagine where you'd build something that size.
Belfast Harbor Manager Michael Robinson doesn't have to imagine. It's knowledge he picked up over the last six months as the port has transformed itself into the U.K.'s first dedicated offshore wind construction harbor. Its docks will open in October.
Robinson isn't alone as port managers across Britain weigh up the offshore wind sector as a source of revenue and jobs. A rush of development is expected through 2020, driven by government ambitions to install over 2,500 turbines capable of producing as much as 18,000 megawatts of electricity, up from 1,500 megawatts today. The government describes the target as ambitious but nonetheless expects installations to pick up once subsidy policy debates are settled. Offshore wind accounts for just over one percent of the country's energy mix today and is expected to rise to about 12 percent by the end of the decade.
Preparing ports for offshore wind development isn't as easy as clearing away shipping containers and buying bigger cranes. The foundation for an offshore wind turbine alone can weigh as much as 600 tons, a little less than a World War II German U-Boat submarine. The turbines themselves weigh about 400 tons.
Port authorities need to strengthen docks so they can handle loads of between ten and fifteen tons per square meter -- three times what's needed for a normal commercial pier. Some ports will also need to a build a so-called "jacking layer" under the harbor to allow offshore wind rigs to stand on their supporting legs within the port.
Few ports are investing the 50 million pounds ($79 million) Belfast has and none has tapped a 60 million pound government fund available to build offshore wind manufacturing facilities at English harbors. Belfast's investment hinged on a ten-year commitment by Denmark's Dong Energy A/S to use the facility as its main Irish Sea construction hub, Robinson said. "They needed a port for at least five, probably ten, years and that gave us the confidence to invest," Robinson said. "Other ports have struggled to find counterparties, and the mathematics doesn't work without that."
There's competition for the docks if the wind developers can't secure them. "Most U.K. ports aren't sitting empty waiting for offshore wind developers to come along and use them," said Dennis Henderson, Peel Ports business development director. Other uses could include the construction of nuclear power stations and biomass importers and generators, which need to be located close to a port to receive materials to be burned, he said.
Visit www.bloomberg.com/sustainability for the latest from Bloomberg News about energy, natural resources and global business.