In order to assess the impacts of various incentives in use, we select current state-level solar PV incentives from each location. Arizona, Georgia, Massachusetts, and Oregon were chosen to capture regional variation in physical and policy climates. Analysis focuses on incentives promoting commercial-scale projects, at least 1 MW in size, rather than small-scale residential (distributed generation) programs. Note that results may not apply to dis- tributed generation due to increased maintenance costs from pa- nel cleaning across many locations, and to limitations in east-west tracking in small scale installations (this in turn limits the amount of incident solar radiation a panel may convert to electricity).
To streamline analysis, we assess the impact of each policy in
isolation, though states sometimes employ multiple incentives. We also elect not to speculate on a particular power provider's line of credit and relationship to its regulators, taxers, and other poli- tical players. This simplifies the Eq. (5) by dropping fiscal terms unrelated to incentives.