ABB provides HVDC transmission technology for offshore wind farms

ABB provides HVDC transmission technology for offshore wind farms
September 15, 2008 - ABB is providing the technology that will enable a unit of E.ON, Germany's biggest utility, to link the world’s largest offshore wind farm to the German power grid at minimal impact to the environment.

The 400-megawatt (MW) wind farm, located 130 kilometers from the coast in the North Sea, is expected to save carbon dioxide emissions of 1.5 million tons per year by avoiding the need for additional fossil-fuel generation.

ABB is connecting the park – the most remote wind farm in the world – using high-voltage direct current (HVDC) transmission technology. Although HVDC has been available for more than 50 years, ABB’s development of the technology to produce the related HVDC Light about 10 years ago provided the technological means to build wind parks far from the coast.

“The project is unique,” said Karl-Heinz Lampe, Managing Director for E.ON Netz Offshore. “Politicians in Germany are following the project NORD E.ON 1 with special interest and it has also drawn considerable attention from abroad.”

Germany aims to generate 20 percent of its power from renewable sources by 2020, compared with about 14 percent in 2007. Wind power accounted for about 40 percent of Germany’s electricity from renewable sources last year, but with the best onshore locations already developed, the country’s utilities are turning to offshore sites.

The main attraction of going offshore is the enormous wind resource available. Average wind speeds can be 20 percent higher than on land, and the resulting energy yield from wind farms as much as 70 percent higher.

While three-phase alternating current (AC) links are a cost-effective way to connect small offshore wind farms near the coast to the electricity network, HVDC Light has emerged as the technology of choice for more distant offshore parks.

Power can be fully controlled using HVDC Light, so that the intermittent electricity supply from a wind farm cannot disrupt the grid. An HVDC Light transmission system can also be started from a powerless state, for example if the wind hasn’t been blowing at all, and very little electricity is lost during transmission, even over long distances.

The use of oil-free cables running underwater to the coast, then underground to a substation 75 kilometers inland, are further ways in which the transmission technology minimizes the environmental impact of the NORD E.ON project. The 80-turbine farm is scheduled to enter service in 2009.

Offshore wind-power capacity, though currently small, is growing faster than onshore capacity. The 20 countries that are members of IEA Wind, a branch of the International Energy Agency, increased offshore wind capacity by 26 percent in 2007 from 2006, compared with a 21-percent increase for onshore capacity.

ABB is the world's largest supplier of electrical products and services to wind turbine manufacturers, with a portfolio ranging from generators to compact substations to grid connections.

ABB is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs more than 115,000 people.