Enhanced Solar PV Deployment


Deployment of distributed solar PV generation, principally behind-the-meter solar PV systems on residential and commercial rooftops, is accelerating across the U.S. More than 2 million PV systems were interconnected to the electric grid by early 2019, up from approximately 475,000 systems installed near the final quarter of 2013. Of PV systems currently installed nationally, more than half have been interconnected in the western states. In recent years, the number of interconnection requests have grown substantially in the most robust solar markets in the West, such as California, Arizona, Colorado, Nevada, and Utah.


In spite of optimistic projections for distributed solar photovoltaic (PV) generation in the Western U.S., barriers to solar PV deployment exist and their mitigation or removal could facilitate deployment. The Western Interstate Energy Board (WIEB), along with the National Renewable Energy Laboratory (NREL) and the Lawrence Berkeley National Laboratory (LBNL), will conduct research to facilitate mitigation/removal of barriers to distributed solar PV generation.


Barriers to solar PV deployment, as noted above, do exist. These barriers fall into three broad categories:

  • certain challenges to distributed solar PV interconnection with the grid; and
  • potential grid reliability concerns; and
  • concerns with utility rate design

WIEB and its national laboratory partners will work with Technical Advisory Committees to identify and define perceived barriers to deployment of solar PV; conduct research concerning the perceived barriers; identify and define measures that could mitigate or remove the barriers; and conduct outreach to state policy makers and regulators to facilitate mitigation or removal of the barriers.

Total funding for this work is approximately $2.5 million. The work began in early 2017 and will be conducted over years 2017-2019.

Research Reports

Interconnection barrier
Reliability barrier
Utility Rate Design barrier
Additional Resources
  • “Stability and control of power systems with high penetrations of inverter-based resources: An accessible review of current knowledge and open questions.”
    • This paper, available HERE, explores current knowledge and open research questions concerning the interplay between inverter-based resources (IBRs) (e.g., wind and solar photovoltaic) and cycle-to second-scale power system dynamics, with a focus on how stability and control may be impacted or need to be achieved differently when there are high instantaneous penetrations of IBRs across an interconnection.


For more information about this project, please contact Maury Galbraith at WIEB: mgalbraith@westernenergyboard.org