Here comes the Sun

It can feel challenging in the world right now to hold onto our optimism for the future, as we do our best to face down the many hurdles of the pandemic. But those of us who work in the field of solar power research are feeling very fortunate. We have so much to feel not only optimistic about, but hugely excited for where this technology is continuing to take us both in Australia, and as a global community.

That each year brings us closer to a world that will be completely powered by sustainable energy sources within so many people’s lifetime is thrilling, to say the least. It’s become clear in the last two years that a sustainable energy system that can withstand all kinds of supply chain shocks is going to be critical in moving our society to a place where it will be resilient in the face of similar challenges.

As for why we should feel optimism, the numbers speak for themselves: Australia has been a long-term world leader in rooftop solar adoption; right at the top internationally even without having to normalise per capita. Each year we become less and less reliant on fossil fuel generation to power the grid. The cost of solar power has also come down to an affordable price for everyday energy consumers with incredible speed, and is now the cheapest form of power generation there is.

Silicon is incredible at what it does, but it’s like comparing a Nokia to what an iPhone can do.

For myself, it’s been a long and extremely satisfying journey to this point as a solar engineer. I’ve been so inspired to have spent over 40 years in the field, and to have been in a position to help foster a pioneering culture of innovation that has over those decades produced incredible leaps in technological advances for solar power. Being at the very forefront of where new technologies are developed and then put into use everywhere is what keeps all of us energised (excuse the pun) about our work. It’s an incredible place to be.

But even people passionate about sustainability might not realise that solar power as it exists today, even with its massively impressive proliferation around the world, is in many ways still a young technology. The first major battle for our team at UNSW with the PERC cell in the 1980s was proving that the concept was viable, which we did. But the work from there that went into commercialising the technology at scale was an enormous task of global co-operation, and it’s only in the last decade that we’ve seen solar take off in the way that it has. Australians can feel proud of our role in this, both through PERC and our role in getting the industry set-up in low-cost Asian regions, via Australian joint ventures.

Which is why now is such an exciting time for our field.  At UNSW Sydney today, I oversee the Australian Centre for Advanced Photovoltaics. Our research centre, under federal government support from ARENA, unites researchers across several Australian and international universities, and in partnership with CSIRO and industry, facilitates the work of hundreds of engineers who are working on improving every aspect of current and emerging solar technologies.

I’ll use this opportunity now to highlight some of the dozens of research projects that we have underway, which to me point to where the future of solar power is going to take us: a technology that is already becoming cheaper, more powerful, longer lasting and sustainable as researchers push it forward.

Here at UNSW we do a lot of work with the materials that constitute solar cells themselves. For many years silicon was the sole material that went into converting sunlight into power through these cells, and it’s still the industry standard. Now some of the most exciting work that will lead us to more powerful kinds of cells, which can generate more power than silicon can alone, is the development of tandem cell stacks. Simply put, this means making a solar cell that uses two layers of material to generate power, which has resulted in far more powerful kinds of cells.

We know the technological solutions to this already exist; that’s how we get up every day and keep working on them.

We like to use the analogy of the mobile phone when it comes to solar cells: silicon is incredible at what it does, but it’s like comparing a Nokia to what an iPhone can do. Our teams are researching materials like perovskites, kesterites and gallium-arsenide tandem cells, which when working together with a base silicon cell, all show exciting potential. There’s a practically limitless array of materials that could be unlocked in this way, and it’s my personal passion area of research, so I greatly look forward to the next few years of development in this dynamic space.

At the other end of the solar picture is the deployment of solar systems themselves, which industry has succeeded in making both larger and cheaper at scale, with systems today that will be able to power entire cities. The amount of sunlight energy hitting Earth’s surface every second is enough to power humanity’s energy consumption for over 2 hours; all we have to do is harness it. UNSW is partnering with Sun Cable on research that will inform the solar tech choices that go into building the Australia-ASEAN Power Link, the world’s largest solar infrastructure project that will export power from the NT to Singapore. To see Australia taking the global lead in this kind of ambitious renewables project is more than we could ever have hoped for back in the 1980s, when we first started working on the solar cells that would go on to power the world.

The latest IPCC report on climate change has shown us that this is the kind of research we need to invest in now more than ever, to ensure we can transition the world to a sustainable energy system in time to ensure the future our younger generations deserve. Those of us working in the field of research and development in renewable energy know that the technological solutions to this already exist; that’s how we get up every day and keep working on them. We need to stay hopeful that a continued commitment to our work will drive innovation and industry advances, and that our leaders will show a similar commitment to investing in the future for all of us.

NOTE: Martin Green thanks Elmo Keep for her co-writing of this article.