The workshop opened with reports and discussions on PV growth trajectories and challenges around the world, with a focus on India, Europe, China, the USA, Australia, and Kenya. This "trip around the globe" highlighted both the regional opportunities and challenges to PV growth and its contribution in achieving the CO₂ emission reduction targets. A growing number of future scenarios show photovoltaics (PV) as playing a central role, especially in the Sun Belt, in helping countries transition to a sustainable energy system.

“The tremendous learning curve that PV experienced over the past decades has resulted in continuous technological advances, major cost reductions and deployment growth often exceeding predictions,” said Nancy Haegel, from the National Renewable Energy Laboratory. “The workshop participants were very engaged in learning from one another and discussing what the growth and research in the next decade could bring.”

Technology Evolution and Sustainability at Scale

During the workshop, participants discussed PV technologies for the multi-TW era, with a focus on tandem technology, which promises to significantly outperform PV efficiency beyond existing limits. Tandem technologies combine two or more types of materials into one solar cell device, thus achieving the benefits of increased absorption of light from the sun. While there are still some minor challenges remaining to achieve industrial production of a higher efficiency on pure silicon material, industrial-scale tandem technology needs still more research to become reliable. The workshop participants heard from leading researchers and industry partners about their progress and challenges in this area.

Another key topic was the issue of long-term sustainability and circularity for the industry, as it moves toward future steady state production, installation, and replacement at multi-terawatt scale heading towards 2050. Workshop participants agreed that the increased production is bringing a new set of research and development (R&D) challenges to the PV community. Targeted research is needed to drive innovation and support industry efforts to continue to reduce levels of embedded energy and carbon and raw material use, while leveraging global learning and growing diversification of manufacturing in order to continue advancing the performance and reliability of the technology as it is scaled up.

“PV technology has demonstrated increasingly great success and has become a mainstream for the world energy supply. However, more research is needed in order to push the efficiency even higher and to create a circular economy”, said Prof. Andreas Bett, director of Fraunhofer ISE, Germany. He adds: “PV is well on track to provide the majority of the world’s energy in a cost effective, clean and sustainable way.”