Comparing Supply and Demand Models for Future Photovoltaic Power Generation in the USA

We explore the plausible range of future deployment of photovoltaic generation capacity in the USA using a supply-focused model based on supply-chain growth constraints and a demand-focused model based on minimizing the overall cost of the electricity system. Both approaches require assumptions based on previous experience and anticipated trends. For each of the models, we assign plausible ranges for the key assumptions and then compare the resulting PV deployment over time. Each model was applied to 2 different future scenarios: one in which PV market penetration is ultimately constrained by the uncontrolled variability of solar power and one in which low-cost energy storage or some equivalent measure largely alleviates this constraint. The supply-focused and demand-focused models are in substantial agreement, not just in the long term, where deployment is largely determined by the assumed market penetration constraints, but also in the interim years. For the future scenario without low-cost energy storage or equivalent measures, the 2 models give an average plausible range of PV generation capacity in the USA of 150 to 530 GW_dc in 2030 and 260 to 810 GW_dc in 2040. With low-cost energy storage or equivalent measures, the corresponding ranges are 160 to 630 GW_dc in 2030 and 280 to 1200 GW_dc in 2040. The latter range is enough to supply 10% to 40% of US electricity demand in 2040, based on current demand growth.