Portland-based Keppel Prince Engineering has 450 workers on its books, including about 200 who specialise in making towers for wind energy projects.

The company's general manager Steve Garner said he was deeply concerned by new rules for turbine placement approved by Planning Minister Matthew Guy this week.

These include a minimum setback of two kilometres between turbines and homes unless written consent is obtained, a policy the Coalition took to last year's election.

Areas of outstanding natural beauty such as the Great Ocean Road region, Yarra Valley, Bass Coast and Macedon Ranges have been declared no-go zones by the state government, which has also banned wind farms within five kilometres of regional growth areas including Warrnambool, Hamilton and Portland.

Mr Garner said Keppel Prince had put millions of dollars into its south-west operations but may be forced to move its tower manufacturing arm elsewhere.

"At the end of the day, if I can't get that business and get our plant and equipment operating, then I'll take it to wherever it needs to be," he said.

"If that means that we have to move this section of our business interstate, then that's what we will do."

The firm's Singaporean parent company has approved a $6 million painting and blasting facility at Portland if more wind farm work can be secured.

"That's very much still on the agenda, for us to make that investment ? I still have approval to do so but I won't be going ahead with it until we know there's some certainty around the industry," Mr Garner said.

"The industry itself is really in quite a lull. The only wind farm going at this point in time is the Macarthur project, so without that we'd all be in trouble."

Pacific Hydro has confirmed it will complete stage four of the Portland wind energy project, which involves construction of 11 turbines at Cape Nelson North and 16 at Cape Sir William Grant.

But the company said this week it was unlikely to pursue further Victorian ventures given the state government's new rules.

Mr Garner said morale among employees had suffered as a result of further wind farm planning regulations.

"When the government legislated 20 per cent (of renewable energy) by 2020 we thought the 10 years of hard work to get to that was over," he said yesterday.

"Now all of a sudden we've got another brick wall put in front of us."

Mr Guy told The Standard he had met with almost a dozen wind farm developers in recent months.

"The Victorian Coalition government supports renewable energy investment, including wind farm projects," he said.

"But for too long the previous Labor Government ignored the concerns of regional Victorians and treated them like second class citizens by denying them notice and appeal rights for wind farm proposals.

"There are more than 1000 turbines with permits that remain unconstructed."

aweaver@standard.fairfax.com.au