Photovoltaic Power Generation in Flagstaff

GE Global Research and GE Energy Consulting along with NREL, ASU, and ViaSol Energy Solutions have been participating in an Arizona Public Service (APS) led, US Department of Energy funded study of photovoltaic (PV) power systems and the integration of these systems into the power grid.  Our goal is to better understand the issues arising from the application of a large amount of solar electricity generation to the US power grid and to share that understanding with utilities and others in the solar industry.

Screen-Shot-2012-05-25-at-9.28.50-AM-300x224The project, “High Penetration of Photovoltaic Generation Study – Flagstaff Community Power” is a part of the Department of Energy’s High Penetration Solar Deployment Program.  It is built upon a larger pilot project launched by Arizona Public Service in Flagstaff (APS Community Power Project). Approximately 1.5MW of solar generation has been installed along the Sandvig 4 feeder in Flagstaff. Participating residential customers host a total of 1000kW of distributed PV: 600kW is installed as residential rooftop systems sized 2-4kW, and 400kW as larger commercial/industrial systems sized 50-150kW. The remaining 500kW is hosted by APS and installed as a small solar farm located on the feeder. The data collected on this project will enable APS to evaluate how distributed energy impacts its system, and to define guidelines for the design of similar systems in the future.

GE’s collaboration with APS on the High Penetration of Photovoltaic Generation Study provides us with a unique opportunity to study the effects of increasing levels of PV penetration on a typical distribution feeder. The project team recently completed the Phase 2 review with the DoE at APS headquarters in Phoenix, AZ.  The GE 700kW Brilliance Inverter with advanced grid features including low voltage ride through and voltage support has been deployed on the 500kW solar farm and the GE project team was able to show the impact of the inverter on the distribution feeder.  GE Energy Consulting provided system impact and performance evaluation studies including an evaluation of the impact of distributed PV generation on the feeder voltage.  One of the most interesting aspects of this project for GE is that the data acquisition systems designed for this project allows us to see things at a fidelity unequaled to date.  The specially designed data acquisition systems have been deployed at the substation, seven weather stations, 13 residential PV locations and 6 feeder data acquisition systems evenly distributed across the feeder. These DASs collect data at a high sample rate, are set up for cross-triggering, and are directly integrated to the utility data historian, which allows us to rigorously compare and validate our models against actual data from the utility feeder.

Screen-Shot-2012-05-25-at-9.28.07-AM-300x226These results can then be extrapolated to help us to understand other systems, even those that may be significantly larger in scale, and working on this project with APS has also helped our research team to better understand how our products are used by our customers.

Phase 3 of the project is coming soon.  We will have the chance to demonstrate our advanced grid features on the feeder and characterize the results. Ultimately the project team hopes to write a handbook on how to integrate PV into the US distribution grid most effectively and at the lowest cost.