Viking Energy plans to locate the turbines on the main island in an area where the winds are the most powerful in Europe, The Guardian reported. A single turbine near Lerwick has already set a global record for efficiency.
The project has roused considerable opposition in the islands with more than 10 percent of the population lodging objections.
The Royal Society for the Protection of Birds, a former supporter, now says the wind farm could destroy nesting areas for birds like the whimbrel, with 90 percent of the British population nesting in Shetland.
Scottish Energy Secretary Fergus Ewing has already forced Viking to reduce the size of the project to 103 turbines from 127. Ewing said the larger plan threatened safety at Sullom Voe Airport.
Experts say the wind farm will produce enough power for 175,000 homes. Most of it will be sent to Scotland via an undersea transmission cable.