System price dynamics for battery storage

While steep learning curves have been documented for lithium-ion battery packs, little evidence exists on whether total system prices for end-users reflect this decline. We use project-level data from California to estimate system price dynamics and experience rates for battery storage systems. We document low experience rates of about 1.3%, i.e., with every doubling in cumulative projects, system prices fall by 1.3%. Larger systems show higher experience rates of up to 11%, while smaller systems show slightly negative experience rates. We find that limited competition among installers is restraining price declines for small systems. Moreover, learning is driven by industry (rather than firm) experience and is significantly lower for balance-of-system prices. In sum, our results suggest that price dynamics relevant to end-users fall behind the pace of reported cost declines for battery packs, and warrant policy focus on installer competition and balance-of-system costs.