A LEGAL challenge against the controversial $2 billion King Island wind farm proposal could be thwarted if state-owned Hydro Tasmania succeeds in making its opponents find $165,000 as security for costs.

Wind farm opponents, the No TasWind Farm Group, said its legal challenge security cost "tipping point" was only about $20,000.

The Federal Court is likely to make a ruling on the matter in early March.

No TasWind Farm Group vice-chairman Donald Graham said "we have offered them $20,000" in security and any figure substantially more than that, "up to $250,000", was "a ploy on their behalf" to scuttle the challenge.

Hydro has confirmed to The Advocate that the figure was $165,000.

"They have wriggled in every direction to stop it [the legal challenge] from going anywhere," Mr Graham said. "I understand that - that's what lawyers do.

"The tipping point was $20,000. We have pledges for that amount from within the community."

Mr Graham said it would be a "travesty" if the group's court challenge, which essentially argues Hydro Tasmania does not have a social licence for its 200-turbine wind farm and it also failed to get its nominated 60 per cent community support to proceed to its feasibility study stage, did not go the distance because of the costs issue.

Hydro is seeking a ruling that the group's claims "are fundamentally flawed" and it wants the group to  "provide security for the anticipated costs".

Hydro Tasmania recently scored an early win in the legal battle, with the court rejecting a costs bid by its opponents, instead awarding costs to the power provider to be fixed.

Mr Graham said it was somewhat ironic that Hydro was trying to stifle the group's opposition using cost security while "clearly" trying to win some support on the island through local funding initiatives.

Hydro announced grants last December of up to $40,000 per applicant to anyone wanting to investigate the feasibility of establishing an abattoir on King island. Then last month it announced a three- year $60,000 deal to become the naming rights sponsor for the iconic King Island Imperial 20 coast-to-coast race, 20 years after the event was first held.

"That's part of the deal [to boost community support]," Mr Graham said. "It's what happens."

Mr Graham said the controversial project had in some cases divided family members on the island, adding its impact, albeit confined locally, was not dissimilar to the Bell Bay pulp mill in Northern Tasmania's Tamar Valley.

However the proposed wind farm - intended to cover about 20 per cent of the land mass - would be "in your face 24 hours per day", he said.

"I have met a husband and wife - they just stop talking about that," he said. "It's not a good situation. We have the same with fathers and sons, mothers and daughters.

"Some people see it as the saviour of the joint, others see it as the devil."

A student on King island, Jaiden Rainbow, posted an article on the Heywire website late last year describing the "tension in the community" and the progression of the project tearing "an even bigger hole in our already torn community".

The TasWind project, involving the construction of a 600-megawatt wind farm consisting of about 200 turbines, was estimated to create about 500 construction jobs, with 15 subsequent jobs for operators.

Hydro-commissioned consultants expect the southern hemisphere's largest wind farm would deliver "total economic returns to King Island over the life of the project of between $255 million and $310 million" and between $7 million and $8.9 million of "ongoing economic benefit per year", including direct payments of about $3.5 million to landowners and their neighbours.

And many believe the project, which would most likely require Chinese investment, is even more critical after the closure of the Swift Australia abattoir.

Mr Graham said apart from the over-stated claims about the economic benefits to the island, the Abbott government might change the legislated renewable energy targets, making it a "game changer" for the proposal and no longer viable.

He also said there was clearly political pressure at a state government level to build the wind farm so that Hydro could return greater dividends back to the government in the future, especially given the government was all but "broke".

This week the second largest proposed wind farm in the southern hemisphere was given the green light by the South Australian government.

The $1.5 billion Ceres project will be developed across 18,000 hectares near Black Point, on the Yorke Peninsula, and be capable of generating 600MW of electricity through 197 turbines.