Optical innovations for solar modules – which are the most promising?
Experts provide a comprehensive overview of the state of solar research
In 2023, photovoltaic systems generated more than 5% of the world’s electrical energy and the installed capacity doubles every two to three years. Optical technologies can further increase the efficiency of solar modules and open up new applications, such as coloured solar modules for facades. Now, 27 experts provide a comprehensive overview of the state of research and assess the most promising innovations. The report, which is also of interest to stakeholders in funding and science management, was coordinated by HZB scientists Prof. Christiane Becker and Dr. Klaus Jäger.
Photovoltaics (PV) has become one of the most cost-effective technologies for generating electricity. In November 2024, the world’s photovoltaic systems reached an installed capacity of two terawatts, and the growth rates and cost reductions are still enormous.
Expertise from 22 research institutions
‘At a recent workshop, we discussed how the optics community can contribute to the further growth of photovoltaics,’ says Prof. Christiane Becker, head of the Solar Energy Optics Department at HZB. Christiane Becker and her colleague Dr. Klaus Jäger then invited international experts to compile a comprehensive overview of PV technologies and optical innovations. In total, 27 renowned experts from 22 research institutions in 9 countries contributed to the review.
Most promising concepts
The article begins with an overview of the current state of photovoltaics on a terawatt scale. From this, the experts identify issues and topics, where the optics community can contribute to enable large-scale deployment. ‘We have also identified a number of optical concepts that are currently only on the threshold of economic viability, but which hold the most promise for advancing PV technology,’ says Christiane Becker. These include optical innovations in the field of multi-junction solar cells, which have the highest efficiencies and therefore have great potential to further reduce the levelized cost of electricity.
Ecological aspects
Improved manufacturing processes using an eco-design approach and minimising the consumption of critical raw materials are also discussed. Another chapter is devoted to coloured solar modules as building integrated PV solutions. ‘Especially in cities, we need to use facades and other surfaces too for solar energy conversion, and of course, it does matter how the PV modules look. Such innovative solar modules allow sophisticated aesthetic solutions,’ says Becker.
Christiane Becker and Klaus Jäger are convinced that this comprehensive review does not only help the scientific community, but also decision makers in research funding.
Publication:
Advances in Optics and Photonics (2025): Optics for Terawatt-Scale Photovoltaics: Review and Perspectives
Klaus Jäger, Urs Aeberhard, Esther Alarcon-Llado, Benedikt Bläsi, Sven Burger, Bruno Ehrler, Wilfried Favre, Antonin Fejfar, Tristan Gageot, Ivan Gordon, Henning Helmers, Oliver Hoehn, Olindo Isabella, Marko Jost, Martin Ledinsky, Jyotirmoy Mandal, Phillip Manley, Delfina Munoz, Zunaid Omair, Juan Camilo Ortiz Lizcano, Ulrich Paetzold, Aaswath Raman, Hitoshi Sai, Rebecca Saive, Martina Schmid, Eli Yablonovitch, and Christiane Becker
DOI: 10.1364/AOP.530556
Preprint: Optics for Terawatt-Scale Photovoltaics: Review and Perspectives
Contact:
Helmholtz-Zentrum Berlin für Materialien und Energie
Department Optics for Solar Energy
Dr. Klaus Jäger
+49 30 8062-13647
klaus.jaeger(at)helmholtz-berlin.de
Prof. Dr. Christiane Becker
+49 30 8062-15630
christiane.becker(at)helmholtz-berlin.de
Press Officer:
Dr. Antonia Rötger
+49 30 8062-43733
antonia.roetger(at)helmholtz-berlin.de
Press release HZB, 28 March 2025