table 1. The potential outcomes of an integrated approach. Feeder-specific hosting capacities Determine the existing hosting capacity for each feeder across the entire distribution system under current grid configurations Optimal DER location Identify locations that can minimize the upgrades necessary to accommodate DERs Improved fast-screening techniques Improve screening techniques that efficiently account for the proposed DERs and associated grid capacity at that location Substation-level hosting capacities Improve visibility into substation-level capacity for accommodating PVs connected at the individual feeder level Range of issues and costs for accommodating DERs across the distribution system Provide better insight into the specific issues that can arise and where and how often they may occur throughout the system Range of values that can be garnered through widespread adoption of DERs Provide better insight about the true value of widespread DER adoption throughout the system Aggregate amount of DERs across a system for bulk system analysis Identify locations and aggregate DERs for improved bulk system studies Impact of DERs on system reconfiguration Streamline processes that can be repeated in an automated fashion for additional distribution configurations performing hosting capacity assessments with respect to voltage and protection impacts, energy and capacity assessments across the fleet can be performed as well. Various applications can be realized after evaluating the distribution system in a more holistic manner by applying such a method across an entire distribution system and taking into consideration 1) DER characteristics, 2) locational impacts, and 3) grid performance metrics. Several key outcomes of this more integrated approach are described in Table 1. Programmatic Implementation of a Proactive Plan This new knowledge lets utilities develop strategies that can influence the locational deployment of DERs. Distribution utilities can tactically direct DER development to areas of the grid that are better suited to accommodate the resource. Costs associated with the deployment of DERs in suboptimal areas can be avoided. At the same time, the benefits of DERs can be used to support utility operations. DER Distribution Hosting Capacity implemented to accommodate load growth or for contingency reasons. This aspect is critical when there is a need to understand the impacts (in terms of cost and value) of DERs spread across an entire distribution service territory. This streamlined hosting capacity method utilizes the feeder model to determine voltage profiles, short-circuit impedances, feeder topologies, and customer characteristics. Voltage and protection issues related to hosting capacity can be effectively determined by correlating several voltage profiles corresponding to different load levels with the shortcircuit impedance of the feeder and the probable distribution of DERs. The locational distributions and resultant hosting capacities are shown in Figure 7. The number of laterals and the overall feeder topology are also factors instrumental in determining the appropriate hosting capacity. Determining a feeder's hosting capacity is only part of the solution, however. Additional systemwide benefits and impacts can be quantified and garnered through proper analysis. In a manner similar to the streamlined method for A B DER Location C A B DER Location C figure 7. A simplistic illustration of the location and hosting capacity for a streamlined approach. The distribution describes what was evaluated, and the hosting capacity describes the outcome. 28 ieee power & energy magazine march/april 2015