German energy company RWE said Wednesday half of the turbines at what will be the second-largest offshore wind farm are operational.

More than half of the 160 turbines planned for the Gwynt y Mor wind farm off the coast of North Wales are in service. The second half could possibly be in service in time for a final commissioning at the end of the year.

Project Director Toby Edmonds explained the offshore facility is already the largest renewable energy source in Wales, but final operations are contingent upon circumstances beyond the company's control.

"We hope to have all 160 turbines commissioned this side of Christmas but with the impact that the winter weather can have on our program, it may be the early part of 2015 before the wind farm is fully operational," he said in a statement Wednesday.

The wind farm will have a peak operational capacity of 576 megawatts, which RWE says will be enough to meet the energy demands of about 30 percent of the homes in Wales.

The $3.3 billion wind farm facility features two offshore substations and at least six miles of cables.