1. © 2015 Electric Power Research Institute, Inc. All rights reserved. Matthew Rylander EPRI April 20, 2015 Streamlined Method for Determining Distribution System Hosting Capacity

2. 2 © 2015 Electric Power Research Institute, Inc. All rights reserved. Overview  Streamlined Method to Analyze Feeder Hosting Capacity for Distributed Generation –Why do we need it? –How does it work?

3. 3 © 2015 Electric Power Research Institute, Inc. All rights reserved. Why do we need a Streamlined Method?PV Growth  U.S. Annual PV Additions Growth fueled by falling economics, Renewable Portfolio Standards (RPS), financing schemes, net energy metering, greenhouse gas (GHG) emissions reduction initiatives

4. 4 © 2015 Electric Power Research Institute, Inc. All rights reserved. Why do we need a Streamlined Method?Analysis  Feeders

5. 5 © 2015 Electric Power Research Institute, Inc. All rights reserved. Why do we need a Streamlined Method?Analysis VoltageProtectionLoadingControl  Feeders  Issues Impact Total DER Penetration

6. 6 © 2015 Electric Power Research Institute, Inc. All rights reserved. Why do we need a Streamlined Method?Analysis  Feeders  Issues  Scenarios  Hosting Capacity Impact Total DER Penetration Uncontrolled DER Deployment Impact Threshold Optimal DER Deployment Impact Below Threshold Impact Depends Impact Above Threshold

7. 7 © 2015 Electric Power Research Institute, Inc. All rights reserved. Why do we need a Streamlined Method?Analysis  Feeders  Issues  Scenarios  Hosting Capacity Feeders with Similar Characteristics Impact Below Threshold Impact Depends Impact Above Threshold

8. 8 © 2015 Electric Power Research Institute, Inc. All rights reserved.  Load Screens Too Conservative Why do we need a Streamlined Method?Screens Not Conservative Enough

9. 9 © 2015 Electric Power Research Institute, Inc. All rights reserved. What type of Streamlined Method is needed? Capture unique feeder-specific responses Granular As distribution feeders change Repeatable System-wide assessment Scalable Clear and open methods for analysis Transparent Validated techniques Proven Utilize readily available utility data and tools Available EPRI’s Streamlined Hosting Capacity

10. 10 © 2015 Electric Power Research Institute, Inc. All rights reserved. Evolution of Streamlined Hosting Capacity Streamlined Hosting Capacity –Analysis performed in the Utility’s distribution software tool –Minutes compared to weeks –Entire system analyzed Detailed Hosting Capacity Correlation Assessment Streamlined Hosting Capacity

11. 11 © 2015 Electric Power Research Institute, Inc. All rights reserved. What does the Streamlined Method look like?  Interface with utility model in the utility platform to attain: –Voltage Profiles –Currents/Loading –Impedances –Topology  Streamlined Hosting Capacity currently performed external to commercial software

12. 12 © 2015 Electric Power Research Institute, Inc. All rights reserved. How does the Streamlined Method work on a feeder?  Single System Resistance from Source Substation Hosting Capacity

13. 13 © 2015 Electric Power Research Institute, Inc. All rights reserved. How does the Streamlined Method work on a feeder?  Multiple Systems and Topology Resistance from Source Substation Hosting Capacity Must Account for Feeder Topology

14. 14 © 2015 Electric Power Research Institute, Inc. All rights reserved. How does the Streamlined Method work on a feeder?  Distributed Systems Resistance from Source Substation Hosting Capacity

15. 15 © 2015 Electric Power Research Institute, Inc. All rights reserved. Feeder-Level Hosting Capacity Resistance from Source Hosting Capacity Optimal PV Deployment Hosting Capacity Range Non- Optimal PV Deployment Max HC Min HC Impact Below Threshold Impact Depends Impact Above Threshold

16. 16 © 2015 Electric Power Research Institute, Inc. All rights reserved. What does Feeder-Level hosting capacity look like?

17. 17 © 2015 Electric Power Research Institute, Inc. All rights reserved. Outcomes of the Streamlined Hosting Capacity Analysis  This is not a replacement for detailed studies but it does provide guidance to when detailed studies are necessary  Questions Answered –Where is the “optimal” location for DER? –How much aggregate DER can a feeder host? –When my feeder changes, how is hosting capacity impacted? –What is the aggregate level of DER that can be accommodated at the substation level? –What amount of DER can be accommodated across my entire system? –What are the range of issues for accommodating DER across the entire distribution system? = Feeder Level Substation Level Overvoltage Thermal Loading Relay Coordination Voltage Fluctuations Relay Desensitization

18. 18 © 2015 Electric Power Research Institute, Inc. All rights reserved. Final Thoughts…  PV is coming  Need efficient methods to plan for it  Methods will continue to evolve –Consideration of existing distributed energy resources –Inclusion of other types of distributed energy resources –Advanced inverter capabilities

19. 19 © 2015 Electric Power Research Institute, Inc. All rights reserved. Together…Shaping the Future of Electricity

20. 20 © 2015 Electric Power Research Institute, Inc. All rights reserved. Minimum Hosting Capacity Comparison Multiple Issues for One Feeder Utility Class DER Residential/Commercial DER

21. 21 © 2015 Electric Power Research Institute, Inc. All rights reserved. Minimum Hosting Capacity Comparison One Issue for Multiple Feeders Utility Class DERResidential/Commercial DER Preliminary Findings + Effectively identifies when lower hosting capacity values are found + Close match at low hosting capacity + More conservative result at higher hosting capacity + Comparable results for all potential issues + Effective for small-scale (customer-based) and large-scale (utility-sized) systems

22. 22 © 2015 Electric Power Research Institute, Inc. All rights reserved. What about Distributed Residential/Commercial PV? Location from Substation Current Distribution Location from Substation DER Distribution Location from Substation Impact 0.5 MW 1.0 MW 1.5 MW 0.5 MW 1.0 MW 1.5 MW Impact Threshold 0.5 MW 1.0 MW 1.5 MW Location from Substation Hosting Capacity DER Center 2 DER Center 1 DER Center 3 1.5 MW DER Center 2 DER Center 1 DER Center 3 Notes + The streamlined method is not a stochastic analysis but the impacts from different possible DER deployments on the feeder are incorporated under the thousands of analyzed DER distributions. + The impact is not typically linear. Only illustrated here for visualization purposes. + Impact threshold for each issue is adjustable.

23. 23 © 2015 Electric Power Research Institute, Inc. All rights reserved. Every Potential Issue has a Hosting Capacity that also Depends on… Location from Substation Power Extreme Boundary of Possible DER Distribution Characteristics Hosting Capacity Hosting Capacity with Lateral Diversity More Probable Boundary of Possible DER Distribution Characteristics Conservative Hosting Capacity Range Optimistic Realistic Notes + Extreme bounds only possible with large pockets of DER either at the feeder head or end. + Probable bounds incorporate randomness in DER location across feeder. + Lateral diversity indicates higher hosting capacity based on DER distributed across parallel laterals on the feeder. No Issues Potential Issues Issues