Just off the east coast of Denmark, near Copenhagen, lies Middelgrunden. It is an area of shallow water, approximately 2 kilometers from the shore in the Øresund, with a depth ranging from 2 to 6 metres.
Its two notable features are Middelgrunds Fort at its north end, and that it forms the foundation of the Middelgrunden Offshore Wind Farm. The farm consists of 20 towers, each topped by a wind turbine capable of generating 2 megawatts.
The towers form a graceful arc with its centre in the centre of Copenhagen, and its radius the same as the outer limits of the city - so it looks aesthetically pleasing on maps.
The turbines used are the largest examples made by Denmark's Bonus Energy A/S, the world's oldest wind turbine factory. They feature a hub 60 metres above the foundations, and 3 rotor blades, each
38 metres long.
With built-in service cranes, high-protection paint and internal climate control, the turbines are built to last with minimum maintenance. In fact, Bonus have given a 5 year guarantee on the equipment.
The 20 turbines, placed 180 metres apart feed all of their power into tower number 10. This contains all the necessary switchgear to send a 30kV supply back along a submarine cable to the Amager Power Plant on the shore.
The farm is specified to produce around 85,000kWh of energy per annum, which is around 3% of Copenhagen's total electricity requirement.