Utgrunden consists of seven 1.5 MW Enron Wind turbines some 12 kilometres from the Swedish mainland and eight kilometres from Öland island. Researchers, led by expert ornithologist Jan Pettersson, have followed the course of 4300 flocks of birds, or more than 180,000 birds in all, reports Enron's Thomas Stalin.
The analysis began in the autumn, when all seven turbines were erected, though some were not rotating. Bird watchers manned three posts -- on Öland, the mainland and Utgrunden's lighthouse. They saw that the majority of flocks migrated past Utgrunden from a long distance, but those flocks that were headed directly towards the wind turbines reacted noticeably. "They saw the turbines from a few kilometres distance, and then they changed their course," Stalin says.
Eider and other duck species were the dominant sort viewed along with geese and cranes, all of whose routes through Kalmar Strait were mapped in detail. The monitoring has continued into the spring, and Enron plans to keep it up for another three to five years until it has valid enough results to launch a more wide-scale international environmental impact study, Stalin says.
The results support those already conducted in both Denmark and the Netherlands and bird behaviour with regard to both offshore and onshore wind plant.