An international group of researchers from leading solar institutes and companies has outlined a bold roadmap for what it calls the “new era of multi‑terawatt photovoltaics,” projecting that commercial solar module efficiencies could exceed 35% by 2050 thanks to tandem architectures. The team, which presented its findings in Nature Energy, draws on discussions from the 4th Terawatt Workshop, a high‑level PV forum led by Germany’s Fraunhofer ISE, the U.S. National Renewable Energy Laboratory (NREL) and Japan’s Advanced Industrial Science and Technology (AIST).
Their perspective argues that the PV industry is poised to continue a decades‑long trend of outpacing earlier projections on cost, performance and deployment while adding a sharper focus on resource use, lifecycle emissions and circularity. With global manufacturing capacity forecast to reach around 3 TW per year by 2050, the authors frame today’s investment decisions as pivotal for climate, industrial policy and development outcomes.
Tandem modules promise >35% efficiency and lower losses
Fraunhofer ISE director Andreas Bett says solar module efficiencies may exceed 35% through tandem structures by mid‑century, with individual cells pushing beyond 36% and tighter control of cell‑to‑module losses than today’s mainstream technologies. By stacking multiple light‑absorbing materials tuned to different parts of the spectrum such as perovskites on crystalline silicon (c‑Si) or tandem combinations with CdTe and CIGS the industry can capture more sunlight without a proportional increase in area.
Bett expects cell‑to‑module losses to shrink relative to current products, meaning more of the cell’s laboratory performance will be preserved in commercial modules. At the same time, the study projects that module prices could fall by a further factor of two by 2050, extending PV’s long‑running experience curve even as designs become more sophisticated.
Efficiency as the key lever for sustainability
While cost reductions remain central to accelerating deployment, Bett frames efficiency as the decisive lever for the next phase of the energy transition. Higher‑efficiency modules reduce the amount of glass, silicon, encapsulant, framing and land area needed per installed watt, cutting both material intensity and balance‑of‑system costs for large‑scale plants and rooftop systems alike.
According to the study, modules with lifetimes certainly extending beyond 40 years will further improve the sustainability calculus, spreading manufacturing impacts over more kilowatt‑hours and easing pressure on supply chains. The authors argue that this combination of higher efficiency, longer life and lower cost is essential if PV is to expand from today’s terawatt scale to the multi‑terawatt deployments implied by global net‑zero scenarios.
Tandem challenges: reliability, degradation and standards
The researchers are clear that tandem technologies still face critical hurdles before they can dominate commercial markets. New device architectures must demonstrate clearly defined performance metrics, predictable energy yield in the field, robust early‑failure detection and effective management of unknown degradation modes, which remain a concern even for today’s advanced silicon modules.
These issues are especially acute for perovskite‑based tandems, where long‑term stability, moisture tolerance and encapsulation strategies are active areas of research. The paper calls for accelerated work on standards, testing protocols and field‑data collection tailored to tandems, so that banks and developers can underwrite projects with confidence as the technology scales.
Opening the door to new players and diversified supply
One notable conclusion is that tandem innovations across c‑Si, CdTe and CIGS could open space for new entrants and diversify the global supply chain beyond today’s dominant regions and firms. By enabling different material stacks and manufacturing routes, the authors say, the next generation of PV can support a more geographically distributed ecosystem of cell and module producers.
The study also highlights how “sustainability‑driven learning” has already lowered costs and will become increasingly important to secure critical materials as volumes grow. Future industry gatherings like the Terawatt Workshop series, they suggest, will likely pivot toward system‑level and end‑user needs, from grid integration to recycling, rather than focusing solely on cell physics or module price.
Ultimately, the researchers argue that investment, manufacturing and deployment choices made now will deliver “globally transformative dividends” by 2050, in the form of economic growth, jobs, cleaner air and reduced poverty. In that vision, ultra‑efficient, long‑lived tandem modules are not just a technical milestone they are a cornerstone of a multi‑terawatt solar future.