Impact of DG on Californian grid “very low”

1 March 2005 – A two-year study evaluating the effects of distributed generation (DG) on the Californian utility grid has helped “streamline interconnections significantly”, according to the reports conclusions.

The Focus II study, carried out by the California Energy Commission (CEC), also concluded that the impact of DG upon the grid was minimal.

Engineering firm Reflective Energies was contracted by CEC to monitor power quality and voltage fluctuations at 14 generation and interconnection sites throughout the state. Each site was equipped with one Ion 7600 power quality monitor on the electric generator, and another at the point of ‘common coupling’ where the utility power lines meet the customers’ power lines.

Each power quality monitor was configured to monitor multiple energy parameters including voltage, frequency, waveform distortion, harmonics, and flicker. The resulting information helped determine whether power quality events were initiated by the grid, or the DG asset.

The CEC has announced that the Focus III study will expand the monitoring programme to include additional sites, continue the certification of DG, and facilitate further streamlining of interconnection.