Since the 1970s, the cost of solar-energy systems has plummeted by over 99 percent. In a recent paper published in PLOS One, SFI External Professor Jessika Trancik (MIT) and colleagues identify the innovations in various photovoltaic (PV) components that led to this spectacular decline.
Trancik and her co-authors found close to 100 key innovations, some originating in the solar-energy industry but many drawing from other technologies. These were sorted into 10 subcategories that span material quality improvements to “legal innovation.” The study shows a striking example of how a technology’s cost improvement is dependent on a web of advancements across many science and engineering research disciplines.
To connect innovations to costs, the team developed mathematical models to understand how, for instance, an improvement in materials utilization depended on innovations in wire sawing and ultimately affected costs.
Going beyond PV systems, this method of identifying important areas for innovations could provide predictive insight into how to invest in different technologies and which ones might see future drops in cost.
Read the paper "Nature of innovations affecting photovoltaic system costs" in PLOS One (August 11, 2025) at DOI: 10.1371/journal.pone.0320676