SOLAR PV ADOPTION for distribution planning


A large investor-owned utility in the SW United States


A large investor-owned utility in the southwest U.S. needed to understand the likely growth of rooftop solar PV in their service territory at a spatially granular level sufficient to support distribution system planning.


Lumidyne supported the distribution system planning efforts of this utility by simulating the adoption and impact of solar PV in both the residential and commercial sectors using a calibrated Bass diffusion modeling approach, implemented in a System Dynamics framework. Lumidyne applied its SPIDER model to forecast adoption at a spatially granular level. The economic analysis of solar PV systems considered system cost declines over time, tax credits, incentives, and geographically heterogeneous PV production. Diffusion model parameters were calibrated using historical PV adoption data and nonlinear parameter optimization algorithms. The calibrated model was used to forecast adoption over a 10-year time frame, under a range of assumptions regarding future PV costs declines and other driving factors.


The IOU used the results of the forecast to inform their electric distribution system planning, ensuring system reliability while minimizing investment costs to the utility and the customer.


The analysis employed Bass diffusion theory in a System Dynamics modeling construct, permitting flexibility regarding time-varying inputs (e.g., cost, tax credits).

spatially granular forecasts

Detailed historical PV interconnect data facilitating calibration of diffusion parameters at the ZIP Code level. (For Illustration Only)