Carbon-free electricity and a halt to thermal coal exports - both by 2030 - and the revival of an economy-wide carbon price top the climate policies the Greens will campaign on at the upcoming federal election.

The party, which may hold the balance of power in the Senate after the May poll, will also push for a national energy efficiency target and create a public electricity retailer to boost competition and drive down energy bills.

The Greens have set a renewable energy target of 100 per cent for the power sector by 2030 as part of their climate policy goals for the federal election. Credit:Jo Buchanan

The renewables target has been raised from the Greens' previously announced goal of supplying 90 per cent of Australia's electricity from solar, wind or other clean energy sources by the end of the next decade.

At the end of 2018, renewables supplied about 20 per cent of the National Electricity Market, including rooftop solar. By contrast, the Morrison government has not set a target beyond 2020, while Labor is pledging a 50 per cent renewables share by 2030.