Construction costs for energy infrastructure are falling as Australia moves away from fossil fuels and invests in renewable power and new battery storage facilities, the country's peak industry forecaster says.

While power-related investment will rise nearly 17 per cent this year to $10.2 billion on projects such as WestWind Energy's planned $1.7 billion wind farm in Victoria, energy infrastructure costs will fall back to an annual spend of about $8 billion by 2022 on the back of an energy production mix less reliant on coal, the Australian Construction Industry Forum's latest forecasts show.