As long as the penetration of PV on the grid is low, the utility should have no trouble maintaining power quality as the output from PV systems fluctuate. However, even if overall PV penetration levels in a region are low, it is possible to have local “hot spots” where penetration on a single distribution circuit is very high. In this case utilities have concerns that power quality will suffer on that distribution circuit due to the high penetration of PV. [Kauai Island Utility Cooperative] KIUC is testing that hypothesis to the extreme with its 1.2 MW solar farm, by supplying 100% of a distribution circuit with PV during the day. [emphasis added]
Now for the good news: as the utility monitors the distribution circuit on sunny days and cloudy days, with the PV system turned on and the PV system turned off, they are seeing very little difference in the voltage levels, harmonics, and overall power quality between the different scenarios. These preliminary results suggest that utilities could go to very high levels of PV penetration in localized areas without causing problems for the grid. KIUC is continuing to monitor the system, but the initial results look very positive for the PV industry. [emphasis added]
