We currently distribute power to about 950,000 customers using three supply grids located in Copenhagen, in the Frederiksberg district of Copenhagen and in North Zealand. These grids consist of a total of about 20,000 kilometres of cable, overhead lines and underground cables as well as around 10,000 transformer stations.
DONG Energy is examining the possibilities for improving its supply grid, including a replacement of 3,600 kilometres of overhead lines by underground cables in North Zealand. Scheduled for completion in 2010, this project is aimed at protecting the power supply network from weather damage. We are also planning to replace 345 kilometres of overhead lines in Copenhagen.
DONG Energy is one of Europe’s leading wind power producers. We have more than 16 years of experience in operating and servicing wind farms.
We operate and service 586 turbines daily, and we work all around northern Europe. Our work involves servicing turbine gear boxes, hydraulic stations, lifts, transformers and generators, and also parts and safety equipment. Safety is always a priority; we only commence assignments after having conducted a safety review, since we typically work 70-80 metres above the ground.
At present our technicians are transported out to the turbines in service vans or on service ships, but when Horns Rev 2 becomes operative, helicopters may also be used to transport them to the turbines. In addition, Horns Rev 2 will be our first wind farm featuring a platform with living quarters. This will mean that our technicians will not come home after work every day, but work a 14-day shift followed by a number of days off.
DONG Energy is developing the intelligent power grid. How? Well, if for instance a cable by mistake is damaged by an excavator, thousands of homes may be without power for a couple of hours. It takes time to localise the failure and ensure that power is being led to the customers through other cables. Today the cable cannot tell us where is has been damaged.
The first phase of the project is to install automatic equipment in strategic transformer stations. This makes it possible to detect failures much faster. If we are to identify failures manually it may take 30 minutes or more to re-connect our customers to the grid. Using the automatic equipment it will only take a few minutes.
DONG Energy is taking it at step further. We develop automatic equipment that not only tells us where the failure is, it also makes sure that power is re-established through other cables.
The intelligent power grid enables DONG Energy to utilize more efficient surplus power production from wind turbines; especially at night. And in future we can use this technology in electric cars and ensure that the cars are charged when surplus, renewable energy is available.
Working on the intelligent power grid has led to a co-operation with seven leading power companies in the world. The purpose is to exchange experience and ideas and to establish the “best-practice”. The co-operation is headed by IBM and the participants come from the USA, Australia and Europe – represented by DONG Energy.