Global spending on solar was higher than any other energy source last year.

A new UN report says 2017’s 98 gigawatts of new solar capacity was higher than all other technologies.

Australia's spending on solar skyrocketed, making it the highest per capita rooftop residential solar market in the world by a wide margin.

“We're at the leading edge of working out how to integrate that renewable power into the electricity market,” said energy expert Iain MacGill from UNSW.

The green power surge is happening around the world, with the proportion of the world’s electricity being generated by wind, solar, biomass and waste-to-energy, geothermal, marine and small hydro increasing from 11 to 12.1 per cent in 2017.

A total of 157 gigawatts of new renewable power was commissioned in 2017, more than double the 70 gigawatts of fossil fuel capacity.

The big challenge now is for the global energy market to integrate variable electricity sources into the grid, according to report co-author and head of research at the Frankfurt School UNAP Centre, Ulf Moslener.

“The coming phase is mastering the structural change within the electricity sector,” Professor Moslener said.

“[Working out] how to apply business models to energy systems where the energy production costs are effectively zero.”

Australia invested a record $8.5 billion in renewables in 2017 with a price per watt of solar photovoltaics at just $1.40.

This is a big saving on the $6.40 paid 2010, according to the report.

China topped the table with more than $126 billion invested in renewables - around 45 per cent of the total global renewable energy budget.

Although investment is occurring, Australia's ability to develop renewable infrastructure is being stunted by government policy, experts say.