As much as $3 billion in wind farm investments may be diverted elsewhere as the state government dithers over guidelines and reporting procedures, developers and suppliers say.

Companies have been waiting since December 2011 for Premier Barry O'Farrell to settle on rules, such as how close to houses turbines can be installed and acceptable noise levels.

Investors were cheered by last month's federal government decision to leave existing settings in place for the renewable energy target, with the aim of generating 45,000 gigawatt-hours a year by 2020. Industry specialists ROAM Consulting calculate the state's wind generation capacity could soar fifteenfold over the rest of the decade, given the quality of the wind resource and the existing infrastructure.