Solar’s dramatic cost reductions and climate change – five takeaways from Professor Martin Green’s presentation for COP31

In UNSW Scientia Professor Martin Green's COP31 presentation, he explains that solar’s dramatic cost reductions have transformed its potential to mitigate climate change. Rapid adoption is already changing electricity generation, while continued technological advances offer further opportunities to reduce costs and emissions. 1. Solar cell costs have fallen around 100-fold.  Professor Martin Green of UNSW and ACAP explains that silicon solar cell efficiency has increased from less than 17% to 25%, while the cost of a cell has fallen from more than US$100 to less than US$1. He says many people have yet to appreciate how affordable solar has become.

https://youtu.be/xZzjRaRqukc?si=dUg-X-bpI-8DWm2F

2. Solar has reached an historic turning point.  Green says that in 2026, solar generated more electricity than all the world’s nuclear power plants combined, as well as more than the wind capacity installed over the previous decade or two.

3. Solar is expected to overtake coal.  By the early 2030s, Green expects solar to become the world’s largest source of electricity generation, helping reduce carbon dioxide emissions from electricity production and, through electrification, transport.

4. Economics is accelerating adoption.  Green highlights countries generating more than 20% of their electricity from solar, including Australia at 22–23%. Pakistan is a striking example: consumers have rapidly adopted solar panels and batteries because generating their own electricity can be cheaper than buying it from the grid.

5. Further breakthroughs could deliver even greater benefits.  Green’s research has demonstrated solar modules exceeding 40% efficiency by stacking cells made from different materials. Although this approach is not yet cost-effective for immediate implementation, he expects such technology to become commercially viable in the future. Watch the 6 minute video produced by Rob Largent for the UNSW School of Photovoltaics and Renewable Energy Engineering (SPREE).