Global PV researchers, including those from Germany's Fraunhofer ISE US' National Renewable Energy Laboratory (NREL) and Japan's National Institute of Advanced Industrial Science and Technology (AIST), argue that the world needs to install about 75 TW or more of solar PV capacity by 2050. Only at this gigantic capacity level the world will meet decarbonization goals for which there is a need to ensure installations grow by 25% annually over the next decade.
Their argument is that 'lowballing projections for PV growth while waiting for a consensus on other energy pathways or the emergence of technological last-minute miracles is no longer an option'. Instead, a sustained global growth in PV is the prerequisite to achieve a climate neutral global energy system by 2050.
The 75 TW as an estimate is based on the assumption of future global population of 10 billion, falling costs of PV and increased energy consumption in the Global South.
Having already installed 1 TW PV globally in 2022, the world is on track to report another TW of installed capacity by around 2024, as per their estimates.
Going by the planned build out of polysilicon capacity, they forecast a production rate of 1 TW/year by 2028 or even sooner since over the last decade the cost of building a new PV production line has decreased by 50% every 3 years, they claim.
Even when it comes to cell efficiency, there has been a growth of 0.5% absolute/ year on average and larger cell sizes correspond to a rise in power output/cell from around 2.5W to 10W. Things are only going to get better from here, they claim, as it takes about 3 years on an average for cell efficiency in mass production to reach efficiency of champion cell fabricated in the industrial laboratory.
Researchers do take the supply chain issues seriously, along with potential scarcity of materials needed to fuel this growth, especially silver. Nevertheless, research is already underway to replace silver with copper or aluminium which is expected to be available for use in TOPCon and heterojunction (HJT) solar modules.
"To increase material circularity in the future as mass production increases, research and development for eco-design and recycling must be ramped up now. In addition, the PV supply chain must be delocalized, not only to reduce logistics costs and embedded emissions, but also to ensure uninterrupted component supply," states Fraunhofer ISE.
These are the main findings of the 3rd Terawatt Workshop held in 2022 that have now been published in a joint paper titled Photovoltaics at multi-terawatt scale: Waiting is not an option published in Science journal.