Renewable-energy generator Infigen Energy is adding to the mystery of Lake George near Canberra, saying a rare breakdown on one of its turbines seven months ago, causing it to be partially disassembled, is still under investigation.
On his way to Canberra to visit his mother, Sydney man Andrew MacLean noticed the different colours across the partially water-filled lake, and pulled over at the east-facing lookout near the Federal Highway.
It was late in the afternoon when he took his Canon 70D camera with a 200mm lens attached and snapped several photos of the turbines in the distance before continuing to Canberra.
"Looking through these images on the computer [the following morning], I noticed that one of the turbines seems to have fallen off. I can't see any equipment around it indicating that it could be under maintenance," Mr MacLean said.
Turbines from two wind farms can be seen from the lookout – the Capital Wind Farm, which has 67 turbines and has been operational since late 2009, and Woodlawn Wind Farm's 23 turbines, constructed in late 2011.
The 80-metre-high turbines and their 44-metre-wide blades belong to Infigen's Capital Renewable Energy precinct, which came under fire in 2014 from Treasurer Joe Hockey who described them as utterly offensive and a blight on the landscape.
The outburst on radio triggered an angry response from one of the turbine's host farmers, Luke Osborne, who challenged Mr Hockey to a bullfight.
Infigen spokeswoman Marju Tonisson said the bladeless turbine at the Woodlawn wind farm had been off line since the start of this financial year.
Infigen group manager investor relations and strategy Richard Farrell said the blades had been taken down for maintenance.
"The wind turbine had a failure of the main bearing. This is the only known failure of this turbine type and is very rare for wind turbines in general. The cause is still being investigated," Mr Farrell said in an emailed response.
Wind farm critics say once government support is withdrawn, infrastructure will be left behind to rust throughout rural landscapes.
Uncertainty over the Renewable Energy Target has stalled billions of dollars of investment in wind turbines.
But Infigen says once a turbine has been installed, its operating costs for 25-plus years are much lower than revenue that can be achieved from selling the electricity it generates, largely because there are no fuel costs.
"The up-front costs have been paid by the original debt and equity providers. Therefore there is no reason not to continue to operate them throughout their useful lives," Infigen said in its statement.
Infigen says there are no government subsidies associated with wind turbines in Australia. "The renewable-energy target legislation requires that an increasing amount of electricity is generated from renewable sources between now and 2020."
Renewable-energy consumers paid the higher cost of renewable energy through the large-scale generation certificates but, because renewable energy has low operating costs, it displaces more-expensive gas generation, thereby lowering the wholesale electricity costs, Infigen says.