Accelerating Photovoltaic Market Entry with Module Replacement

Today's approach to deploying solar photovoltaics (PV) implicitly assumes that module technology is fixed. Solar panels are installed and expected to operate for the system life of 30 years or more. However, many PV technologies are improving rapidly along several dimensions, including cost, power conversion efficiency, and reliability. Periodic module replacement or planned repowering takes advantage of this technological improvement and counteracts predictable degradation. Here, we show that a module replacement strategy allows a competitive levelized cost of electricity to be achieved with an initial module lifetime of less than 15 years, assuming backward compatibility with the original system design. We also assess the life-cycle environmental impacts of module replacement and find that all commercial PV technologies offer benefits in the majority of impact categories, regardless of the replacement strategy, compared to today's electric generation mix. Module replacement can thus accelerate the market introduction and decarbonization impact of emerging PV technologies that have achieved a competitive module efficiency (≥20%), cost (≤$0.30/W), and lifetime (≥10 years) and have the potential to improve further on all three metrics but lack decades-long field deployment experience. Electricity costs from solar photovoltaics (PV) have dropped by a factor of 10 in the past decade, largely due to module cost reductions. Further gains will require continued innovation in financing, efficiency, and module cost. One promising route is through emerging technologies such as metal halide perovskites, especially in tandem structures; for any new technology, however, proving multi-decade lifetimes is a major challenge. We find that replacing modules periodically can allow technologies with short initial lifetimes to achieve competitive costs. Enabling replacement strategies will require further work on new designs, operating procedures, and financing options. Scaling up module recycling is critical for realizing carbon mitigation benefits without substituting other environmental harm. For policymakers and industry players, module replacement presents an opportunity to maintain low costs while supporting the near-term deployment of high-potential PV technologies. This work highlights an opportunity for emerging high-potential solar photovoltaic (PV) technologies to enter the market sooner than expected. PV modules are conventionally required to operate with minimal degradation for 25 years or more. We evaluate a PV system operating strategy that anticipates periodic replacement of all modules. Shorter-lived modules are later replaced with higher-performing, longer-lived modules, leading in many cases to a competitive levelized cost of electricity (LCOE).