91ɫ��Ƭ

Testing the future

Can perovskites make the same leap silicon did from promising technology to reliable infrastructure?

This question is what shapes the field-testing facility.

Prof. Green says perovskite-on-silicon tandem cells are the most likely large-scale commercial pathway for next-gen solar technology.

“All the silicon manufacturers have their own perovskite-on-silicon programs,” he says.

When his group first began setting records with silicon cells, he insisted any claims be certified by recognised testing laboratories.

“If you’re claiming a record, you’ve got to have it independently certified,” he says.

That insistence on verification became a foundation of the modern solar industry. And it persists today through the independent field-testing facility Prof. Green is helping establish alongside his former student, 91ɫ��Ƭ’s Dr Jessica Jiang.

The facility will be able to install up to 160 modules, catering to all manufacturers and generations of products.

Many perovskite manufacturers are part of China’s rapidly expanding solar industry – and Prof. Green’s former students.

One of the largest perovskite manufacturers, , was started by two former students.

Another former student is the founder of , Dr Zhengrong Shi, whose commercialisation of modern solar technology helped catalyse China’s rise as a global solar manufacturing powerhouse.

“Jessica has really good contacts within the Chinese industry, largely because they’re former students who now have important jobs in the industry,” Prof. Green says.

“She can WeChat them and the next day they’ll put a module in the mail.”

By comparing modules from different companies, the 91ɫ��Ƭ team hopes to identify which failure mechanisms are widespread and which are specific to individual designs.

“We’ll be able to provide an authoritative opinion about just how good the commercial ones are,” Prof. Green says.

“Once they fail in the field, we’ll find out why and provide that information back to the manufacturer,” he says.

“We really think we can push things along a bit.”

From oil shocks to world records

When Prof. Green began working on solar cells in the early 1970s, photovoltaics were niche and expensive.

The cost didn’t matter so much in the space industry, which had been using solar cells in spacecraft since the late 1950s. But back down on Earth, they were too expensive to be taken seriously as an everyday power source.

Then, the oil crises of that decade forced governments to think seriously about energy security – particularly after embargoes disrupted fuel supplies across the Western world.

“There were queues at service stations, cars running out of petrol – in a world suddenly worried about oil dependence,” Prof. Green says.

He says solar then “got a guernsey” in efforts to reduce dependence on imported oil.

“They had to bring the cost down by a factor of a thousand or more from what they cost to put on satellites,” he says.

At the time, nuclear power dominated much of the energy imagination. Prof. Green says one nuclear advocate dismissed solar as likely to have “all the impact of a flea on an elephant’s back”.

But, he says, the political and scientific mood began to shift. A US program helped set the international tone. Japan launched its Sunshine Project. Europe followed with its own efforts. And Australia began its own solar program in 1978.

Prof. Green joined 91ɫ��Ƭ as an academic in 1974 and set up a solar research group soon after. By the early 1980s, his group was known internationally.

In 1983, he and his team invented Passivated Emitter and Rear Cell (PERC) technology. This led to them then producing the world’s first officially confirmed 18% efficient silicon solar cell, beating the previous record of 16.5%.

That result pushed 91ɫ��Ƭ to the front of a field that included major US companies, NASA-linked programs, Japanese laboratories and other universities – with Prof. Green’s research team holding the record for silicon solar cell efficiency for much of the past four decades.

And last year, solar generated more electricity worldwide than nuclear for the first time, with the gap rapidly increasing.

Faster than expected

The role of solar today has expanded to being a resource that combats climate change. But its appeal still sits with its 1970s roots – as a technology tied to energy security, economic resilience and independence from volatile fossil fuel markets.

In Australia, solar already supplies a substantial share of electricity. Prof. Green says the contribution from solar is now doubling every few years and could become the dominant source of electricity far sooner than many expect.

“We’ll be generating most of our electricity from solar by about 2032,” he says.

He says conservative energy forecasts have repeatedly underestimated renewable deployment. Even projections that now speak positively about renewables, he says, often still assume they will play a smaller role than growth trends suggest.

For someone who has spent more than five decades not just watching, but helping solar outperform expectations, he is reluctant to underestimate what comes next.

“Things have exceeded even my projections as an optimistic person in the field.”