The California Energy Commission (CEC) has completed a two-year study evaluating the effects of distributed generation (DG) on the California utility grid. As part of its "FOCUS-II project," the CEC had contracted engineering firm Reflective Energies to monitor power quality and voltage fluctuations at 14 generation and interconnection sites throughout the state. To help gather data from each site, Reflective Energies used a network of ION power quality monitors and software from Power Measurement.

According to Edan Prabhu of Reflective Energies, the findings of this study will help to promote an improved understanding of the DG-grid interface, "and in the long run, may help to support faster, more affordable and reliable interconnections between distributed generation assets and the California grid."

This project, along with the efforts of many others, has helped streamline interconnections significantly. As one measure of success, the time frame for interconnections has dropped significantly even as DG applications are on the rise.

The collaborative consensus-building approach through the Working Group has helped improve communications, has resolved technical issues, and has resulted in a greater appreciation by stakeholders of each other's problems.

DG is becoming more complex—driven by high prices for energy, a need for more reliable energy, energy dependency issues, a desire for clean and renewable energy, and waste disposal issues. There is a continuing need for collaborative resolution of thorny issues. It is recommended that the Working Group continue meeting, perhaps less frequently as the incidence of new issues declines.

California stakeholders should continue to work with the IEEE to keep communications open and cross-fertilize.

The monitoring program found no significant impact of DG, and only one instance of an impact of the grid on DG, caused by a lightning strike. It is recommended that the DG monitoring program be enlarged to monitor more complex sites, and the duration of the monitoring be expanded. It is recommended that other DG monitoring efforts be undertaken. FOCUS-III will begin this effort.

According to the CEC, the project has been worth pursuing. The payback is already large, and promises to be even larger.