Investment in large-scale clean energy projects plunged 56 per cent in Australia last year, dropping to its lowest level since 2016 amid renewed uncertainty over the industry's future.

Data compiled by Bloomberg New Energy Finance (BNEF) says spending on new utility scale renewable energy assets totaled $US3.2 billion ($4.6 billion) in 2019. When spending on other renewables, such as rooftop solar, was included, the drop was 40 per cent, the consultancy said.

A solar farm under construction outside the township of Nevertire in western NSW. Credit:Wolter Peeters

"Australia's major political parties took ideologically opposed clean energy platforms to the May 2019 federal election, once again stymieing any hope of long-term policy certainty," Leonard Quong, an energy analyst at BNEF, said.

"Conditions across Australia's thinly spread out electricity network continued to deteriorate," he added. "Falling loss factors cut revenue expectations for many, curtailment began to bite for some and connection delays were a major source of pain for a few."