With Australia having committed to achieving net-zero domestic greenhouse gas emissions by 2050, the attention now is to getting there, from the national level down to state and local levels.

What would it take for a city in Australia, for example, to be net-zero?

Monash University researchers have been looking into a piece of this problem, calculating how much solar energy the City of Melbourne might create by mapping sunlight.

According to the research published in the journal Solar Energy, the city center could cover nearly two-thirds of its energy needs by crowding solar panels onto sunny roofs.

The figure might be raised to three quarters by replacing the facades and glazing with high-tech solar-panel walls and windows.

According to Jacek Jasieniak, a professor of engineering at Monash and a co-author of the study, turning the dense cluster of energy-guzzling towers into vertical solar arrays makes net-zero cities possible.

Monash University’s article focuses on Melbourne’s core 37-square-kilometre region, including high-rise constructions in Southbank and Docklands, mid-rise residential complexes in South Yarra and North Melbourne, and industrial low-rise in locations such as Port Melbourne.

This small area is accounts for 7.5 per cent of Victoria’s total electricity usage, approximately 3,200 GWh per year.

However, it produces very little energy on its own: rooftop PV uptake is minimal.

They estimated that the City of Melbourne’s entire solar potential was 2,354 GWh per year or 75% of current usage.

Rooftop solar panels would generate most of the electricity (88%) generated.

This begs the question: why not just import the energy?

The arguments for generating energy locally come down to cost and resilience.