Bulk System Reliability Impacts of High Levels of Distributed Energy Resources

Many of the emerging resources expected to significantly impact the power system will be distributed resources that are integrated on a decentralized basis at MV or LV levels. These distributed resources include various types of distributed generation including solar PV, various demand response programs, plug-in hybrid electric vehicles (PHEVs), and stationary distributed energy storage. While these resources offer potential benefits to the bulk system, there are potential adverse bulk system reliability implications with widespread proliferation of small distributed resources that are not visible at the bulk system level. Potential adverse impacts may include abnormal voltage/frequency ride-through, voltage stability associated with displacement of dynamic reactive resources, reduced effectiveness of under-frequency load shed schemes, and general lack of visibility and control. This panel will present analysis of the potential magnitude of bulk system reliability impacts of high penetrations of distributed resources, actual operating experiences, and potential mitigating options.