Photovoltaics are growing faster than expected in the global energy system

Dramatic cost reductions and the rapid expansion of production capacities make photovoltaics one of the most attractive technologies for a global energy turnaround. Not only the electricity sector, but also transport, heating, industry and chemical processes will in future be supplied primarily by solar power, because it is already the cheapest form of electricity generation in large parts of the world. This is where opportunities and challenges lie - at the level of the energy system as well as for research and industry. Leading international photovoltaic researchers from the Global Alliance for Solar Energy Research Institutes describe the cornerstones of future developments in an article published in the journal "Science" on 31 May.

The Global Alliance for Solar Energy Research Institutes GA-SERI consists of the Fraunhofer Institute for Solar Energy Systems ISE, the National Institute of Advanced Industrial Science and Technology AIST (Japan) and the National Renewable Energy Laboratory NREL (USA). Since 2016, this international group of experts, expanded by researchers from other groups and countries, has regularly discussed the challenges for the use of photovoltaics to achieve global climate goals. 

HZB Solar Energy Expertise:

Prof. Dr. Rutger Schlatmann, expert for photovoltaics and director of PVcomB as well as division spokesman for renewable energy at the Helmholtz-Zentrum Berlin, also contributed to this expertise. He emphasizes not only the great potential of photovoltaics for climate protection, but also the enormous opportunities for the economy associated with it. The traditionally strong photovoltaic research at HZB has been expanded in recent years on solar fuels as well as novel materials for batteries and catalysts for more energy-efficient chemical processes and thus fits perfectly with the vision described in the Science Paper.

Selected Results:

In a nutshell, you will find selected results from the expert report here. The long version can be found on the website of the Fraunhofer Institute for Solar Energy Systems or directly at Science.

PV capacity is increasing faster than expected

• By 2018, 500 gigawatts of PV capacity had been installed worldwide.
• In 2030, experts expect 10 terawatts of installed PV capacity worldwide.
• By 2050, experts expect 30 to 70 terawatts of installed PV capacity worldwide.

PV will become one of the cheapest technologies

The learning curve for photovoltaics shows from 1976 to 2018: costs are reduced by 23 % per doubling of installed capacity. Experts believe it is likely that this cost reduction will continue.

In Germany, the kWh of solar power, at 4-10 € cents, has long been below the end customer price (>25 € ct/kWh), but now also below the prices for large-scale industry.

Higher efficiencies are in sight

With silicon PV, which covers 95 % of the world market, the trend is towards low-cost solar cells with passivated contacts that enable higher efficiencies. Technological advances in the field of thin-film technologies have raised efficiency levels above the 20 % mark, while the figure for multiple solar cells based on silicon is already over 35 %.

Outlook on sustainablility, networks, storage and sector coupling

For production in the terawatt range, issues of material supply (especially for rare elements such as silver), sustainability and recycling will come more into focus. Networks and power electronics, storage, sector coupling and power to gas can be further developed to absorb a high proportion of solar power. The technologies are already available.

To the publication:

Science, 31 May 2019: »Terawatt-scale photovoltaics: Transform global energy – Improving costs and scale reflect looming opportunities«

DOI: 10.1126/science.aaw1845

Authors: Nancy M. Haegel, Harry Atwater Jr., Teresa Barnes, Christian Breyer, Anthony Burrell, Yet-Ming Chiang, Stefaan De Wolf, Bernhard Dimmler, David Feldman, Stefan Glunz, Jan Christoph Goldschmidt, David Hochschild, Ruben Inzunza, Izumi Kaizuka, Ben Kroposki, Sarah Kurtz, Sylvere Leu, Robert Margolis, Koji Matsubara, Axel Metz, Wyatt K. Metzger, Mahesh Morjaria, Shigeru Niki, Stefan Nowak, Ian Marius Peters, Simon Philipps, Thomas Reindl, Andre Richter, Doug Rose, Keiichiro Sakurai, Rutger Schlatmann, Masahiro Shikano, Wim Sinke, Ron Sinton, B.J. Stanbery, Marko Topic, William Tumas, Yuzuru Ueda, Jao van de Lagemaat, Pierre Verlinden, Matthias Vetter, Emily Warren, Mary Werner, Masafumi Yamaguchi, Andreas W. Bett