No TasWind Farm group president Jim Benn said Hydro Tasmania chief executive Roy Adair committed to a cut-off of 60 per cent of respondents to a community survey in favour before the company would commission a feasibility study.

``I think it stinks - they said 60 per cent, they reneged on that, what else will they renege on?'' Mr Benn said.

But Hydro Tasmania director of corporate services Andrew Catchpole said what the company had committed to and achieved was broad community support.

``We indicated that a simple majority of 50 per cent plus one would not be enough, and that we were looking for a significant number, and the indication we gave was about 60 per cent,'' Mr Catchpole said.

``We don't think we have reneged on a promise.''

The board of the government-owned company yesterday unanimously voted to proceed with a feasibility study, after a survey of 878 King Islanders returned 58.77 per cent support.

King Island resident and wind-farm supporter David Kerr said the support was astounding given the ``unbalanced, negative campaign'' against the project.

Mr Catchpole said the study would focus on the main concerns of residents - the visual, health and noise impacts of the 200-turbine proposal. 

It will develop a model showing the location of the turbines and examine the potential impact on the King Island brand.

The full feasibility study is expected to take two years.

Mr Catchpole said another vote would be taken before construction began, but would not say how it would be conducted or quantify the support required.

Hydro Tasmania has said the project would be worth up to $310 million to the King Island economy and create up to 500 jobs in construction.

King Island Mayor Greg Barratt said the island, which lost its abattoir in September, ``desperately needed something''.

``The feasibility study may change people's minds when they see what we are offered,'' Cr Barratt said.