Market forces rather than subsidies are now driving investment in renewable energy, says an official analysis that also shows wind and solar penetration will reach a level the former Abbott government legislated to prevent.

However, the Clean Energy Regulator (CER) report says the strength of future renewables investment remains "uncertain", and analysts warn the boom will inevitably end, stymieing efforts to reduce greenhouse gas pollution.

The regulator said 2018 was the year that commercial factors overtook subsidies as the main driver of renewables investment. Credit:Glenn Hunt

The government's renewable energy target has been the dominant driver of the move from fossil fuels to renewable energy sources since it was introduced in 2001.

The scheme creates a financial incentive for new power generation from solar, wind and other zero-emissions sources, to meet the goal that 23.5 per cent of Australia’s electricity in 2020 is generated without emissions. The target expires next year and the Morrison government will not extend it.