Origin Energy and Zen Energy Systems are to build a 3MW solar system on the rooftop of the old Mitsubishi factory in Tonsley, Adelaide, in what will be the largest rooftop solar array in the country.

The awarding of the contracts was announced by the South Australian government this week. The intention to build the array was first announced late last year.

Origin Energy will own the rooftop array and sell the output to the tenants of the Tonsley high tech centre (artists impression to the right), under a power purchase agreement that it is looking at replicating elsewhere in the country.

Indeed, Origin Energy managing director Grant King says the company is “changing its view” on electricity markets, and is particularly interested in the economics of utility-scale solar in Australia.

“We are working hard to understand economics of utility scale solar in Australia,” King told an analysts briefing.

Origin has also revealed it has bought a 40 per cent stake in the 69MW Javiera solar project in Chile (pictured right), which is being built by SunEdison in the Atacama desert, without subsidies, and will supply electricity mainly the nearby Los Pelambres copper project.

Origin Energy says this will also help it understand the economics of large-scale solar – both in international markets, and in Australia.

Zen – a tenant in the Tonsley complex – has been awarded the installation and maintenance contract.

“It’s a great job to get to ramp up our capacity and profile with a number of multi-megawatt jobs in the pipeline currently evolving for ZEN around Australia,” managing director Richard Turner said.

South Australia Innovation Minister Kyam Maher said the tender for the 3MW solar project had attracted a huge response from tenderers.

“Tonsley is fast gaining a reputation as an innovation precinct with a focus on sustainability and urban renewal, so it’s not surprising that a project of this size has attracted significant interest,” he said.

Climate Change Minister Ian Hunter said the project would add to South Australia’s credentials as a national leader in renewable energy.

Hunter noted that South Australia has 41 per cent of the nation’s operating wind farm capacity and one in four households have rooftop solar panels.

“If South Australia was a nation, we would rank second only to Denmark as the world leader in terms of installed wind power on a per capita basis,” he said.

Origin’s head of energy markets, Frank Calabria, said the company was delighted to be named preferred partner for the innovative Tonsley project, which will see Origin build, own, and retail the electricity generated by the 3MW solar array.

“We are excited about this project, which will be the largest rooftop solar array Origin has installed, as it builds on our solar leadership and demonstrates our renewed focus on our solar business.