Which PV is better? Distributed rooftop solar PV vs centralised PV power sources

Rose Mary Petrass

Here’s some new research out there that will help you choose which type of PV array is best for you and your business. 

A new report called Rooftop PV vs. Centralised PV: A cost-benefit analysis has been released by the Australian PV Institute (APVI), the lead member-based organisation representing Australian experts in the International Energy Agency’s Technology Collaboration Programmes across two solar energy research areas.

This study, funded by The Australian Renewable Energy Agency (ARENA) and the APVI and conducted by Ekistica, focusses on PV power sources in Central Australian remote communities. 

But even if you don’t live, work, or have clients in the outback, you’ll be wise to pay attention to the results which show that distributed rooftop solar PV totally trumps centralised PV power systems. 

It found that there are serious benefits to supporting existing power stations in remote Indigenous communities with distributed solar PV on household rooftops, compared to a centralised ground-mounted PV system. 

What does this mean? 

Well, to spell it out in plain English for the less technical-minded among us:

  • Distributed rooftop solar photovoltaics (PV) are the most common type of installation, mounted to the roof of the home or building. Solar racking, which holds the panels in place, is installed directly on the roof. 
  • A centralised ground-mounted PV system is when the panels are secured to a rack structure, connected to the ground with steel beams or metal posts. Ground mounts can be installed in an open area.

The results show that distributed rooftop solar PV is far superior. However, keep in mind that the rooftop PV in this study differs from conventional residential rooftop PV systems, because they don’t service individual loads of residential sites that they are installed at.

How did they get these results? 

A technical consultancy firm based in Central Australia called Ekistica compared an aggregation of rooftop PV with centralised ground-mounted solar, both integrated with the central power station in the community, generating power in conjunction with existing diesel generators.

The study investigated the economic benefits to the Power and Water Corporation, comparing sources of solar to support community loads in remote communities serviced by PWC’s not-for-profit subsidiary Indigenous Essential Services Pty Ltd (IES).

The authors ran technical and financial modelling in three communities in central Australia – Kaltukatjara, Lajamanu, and Maningrida. These locations were chosen to represent a range of climatic conditions, geographical regions and population sizes that typically exist in IES communities across the Northern Territory. 


The study found that rooftop PV has the advantage of lower capital costs, and lower operational costs and maintenance requirements.

“The study found that rooftop PV systems can deliver similar levels of technical outputs – generation, renewable energy fractions and fuel savings – as centralised PV systems,” Australian IEA PV Power Systems Task 18 Expert and report co-author Lachlan McLeod noted. 

Lachlan also noted that “the deployment of distributed rooftop PV systems in remote communities would however present operational and project management challenges not seen before with centralised PV systems – not the least of which would be community consultation and obtaining social licence, as well as schemes for reliable control and integration into the existing power system. There is clearly a lot of research and work to be done on that front.”

The decision to choose the right PV isn’t just a financial one. The business case should include social, environmental, and regulatory issues that may be present at each site:

  • regulatory approvals
  • social licences from all households selected for installation
  • disruption of daily routines of households during installation
  • engagement with community members around the stewardship, operation,
  • and distribution benefits of the system
  • environmental impacts of the PV system

While noting the potential social, environmental, and regulatory limitations of distributed PV systems, the study concluded that there are significant economic benefits from installing distributed rooftop PV as opposed to centralised ground-mounted PV. 

  • SunMan supplies unique, glass-free solar panels that are a quarter the weight of conventional solar panels and have the same power output
  • Planet Ark Power is aiming to fill all the open roof space on warehouses and other industrial and commercial buildings to feed the solar energy into the grid
  • Moreland Energy Foundation is a Greenlister which is making sure no one left behind in the energy transition
  • CRC for Low Carbon Living is a Greenlister that gives consumers the power to manage their power bills better

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Rose Mary Petrass

Bye for now. Get in touch if you have any interesting business news for us to report, or if you’re an existing Greenlister and want to share what you’re up to: hello@thegreenlist.com.au

– Rose Mary Petrass, your Green List curator