Wind farm decommissioning to leave giant concrete and steel foundations buried forever 

The 14 giant concrete and steel bases of Australia’s once biggest wind farms will be left in the ground.

There is much public interest in how a power company goes about decommissioning one of the nation’s first commercial wind farms. A public meeting is being held in Victoria’s coastal Port Fairy today (Tuesday) as Pacific Blue unveils its plans for Codrington Wind Farm’s dismantling over the next two years.

It now plans to remove the circular “concrete pedestal” which directly attaches to the turbine tower itself, but leave the bulk of the base buried in the ground. The entire wind farm’s foundations are thought to weigh about 20,000 tonnes in total.

The China-owned company says it is well aware of the public and industry focus on the dismantling of Codrington, and agrees it will set a precedent for the many to follow. There are at least 31 other wind farms also reaching the end of their lives.

There are at least 3000 active turbines which have already been built around Australia across 110 wind farms as the nation pursues a renewable energy future. Wind farms have a typical life expectancy of about 25 years. Solar farms have a similar timeline.

How energy companies owners plan to remove the huge structures and concrete bases is worrying many people in the rush to renewables. Codrington, built at a cost of around $33 million, was one of Australia’s first commercial wind farms and Australia’s biggest when officially opened in 2001 at Port Fairy, between Warrnambool and Portland.

There are currently four other wind farms operating in the region. Its owners are now talking to landowners and authorities on their decommissioning plans, saying the 14 turbines cannot be updated to modern standards.

A Pacific Blue spokesman said the company will be at the forefront of responsible decommissioning in Australia. “There is currently no international or global standard for the decommissioning of wind farms,” the spokesman said.

“We are determined to help enable pioneering Australian solutions that can set an example for the global industry, as well as satisfying local expectations. As a result, we are funding two streams of research, one with UNSW to recycle fiberglass and the other with PVC separation to remove the composites,” the spokesman said. This research is now underway and we hope our funding helps establish new methods that may in the future be suitable for recycling blade materials in Australia.

“Pacific Blue will remediate the turbine hardstands and other energy infrastructure within 12 months of final generation, as required by the site’s permit. The 1.5m pedestal will be cut and removed. The subterranean concrete will remain and be covered with earth and subsequently, vegetation. Regulators will oversee our work, as we are committed to meeting their standards while respecting the land that has supported electricity generation for more than 25 years.”

Pacific Blue executives will today outline plans to use cranes to dismantle Codrington’s towers which are made of steel, aluminium, copper and cast iron. The giant blades are more of a recycling problem being made of epoxy and composite materials like carbon fibre and fibreglass.

Less had been known about the future of the massive concrete and steel bases. Some modern wind turbine foundations require 650 cubic metres of concrete and 85 tonnes of reinforcing steel mesh. At Codrington, the base would be covered in a layer of soil and revegetated “to return the ground to its former state”.

Permit conditions require decommissioning to be completed within 12 months of the wind farm ceasing generation. Permit conditions require the three affected host landowners to be “satisfied” with the rehabilitation of their land after decommissioning so it can return to stock grazing.

Codrington’s ageing wind turbines are rated at 1.3 megawatts apiece with a hub height of 50 metres and blade tip height of 81 metres which are today old tech. When built, Codrington’s location was said to be “close to perfect” powered by strong prevailing winds blowing off the Southern Ocean. Moyne Shire Council’s planning permit for the wind farm issued in 1999 included a requirement “that all turbines and foundations be removed and the land be reinstated to the satisfaction of the responsible authority within 12 months of the use ceasing”.

“The land where the turbines are located will be rehabilitated to the satisfaction of the landowners and the regulatory authorities,” the company has also said.