Re-DEC Working Group Meeting Potential Challenges to High Penetration of Distributed Renewable Generation

1. Re-DEC Working Group MeetingPotential Challenges to High Penetration of Distributed Renewable Generation December 9, 2009

2. Purpose of Presentation • Present initial thoughts on barriers or issues with interconnection of distributed renewable generation • Identify if challenges are: • Prevalent today (near-term) • Can be solved with relatively minimal effort • Discuss potential solutions Black & Veatch - 2

3. Today’s Focus • Want to encourage open dialogue, but want to focus on scope of today’s meeting • Not re-debating Feed-In-Tariff or Renewables Auction Mechanism • Dialogue to focus on solutions and not problems • Please review entire matrix before bringing up new challenges Black & Veatch - 3

4. For this Workshop, What Do We Mean By Distributed Renewable Energy? • Generally we are focusing on: • Wholesale distributed generation • 1-5 MW in size • Connected to distribution system • Probably located at customer sites, but not behind the meter • Solar photovoltaics • Non-Solar DG have some similar challenges Black & Veatch - 4

5. Literature Reviewed • Literature reviewed from the following institutions: • Institute of Electrical and Electronic Engineers • Department of Energy • California Public Utilities Commission proceedings and comments • Federal Energy Regulatory Commission • California Energy Commission • National Renewable Energy Laboratory • Sandia National Laboratories • Academic Papers • Other sources • Systems • Spain • Italy • Canada • Germany • United Kingdom • United States But, every system is unique! Black & Veatch - 5

6. Draft Challenges Matrix • Developed based on literature review, discussion with utilities and developers, comments from CPUC 33% RPS Implementation Preliminary Results report, etc. • Identifies potential challenges ranging from technical to market • Meant to be inclusive – have not tried to “trim” the list much • Want to get feedback from stakeholders if they view these as issues for them • Eventually we will prepare roadmap of potential solutions, timing, cost, etc. Black & Veatch - 6

7. Challenges: We Want to Explore Near and Long-Term Issues • Near-term (<1 year) • What issues are utilities and developers facing today? • What are the potential issues associated with the FIT programs? • Long-term (>1 year) • What would happen if we installed 15,000 MW of Renewable DG? (Current peak ~50,000 MW) • What if solar cost 1 cent/kWh? Black & Veatch - 7

8. Solutions: There are many Possibilities, from Low to High Effort • Dedicated Feeders • Forecasting Solar • Cluster Systems – Develop “Solar Grid Overlay” • Energy Storage • Smart Grid, for example: • Dynamic monitoring and control • Re-Sectionalizing • Load Control • Institute a First Pass / Fatal Flaw Interconnection Application • Curtailing Generation • Increase Substation and Feeder Information Available to Developers • Update Inverter Standards • Load Tap Changers, more Capacitor Banks • Low Voltage Ride Through Black & Veatch - 8

9. Solution Effort Challenge Timeframe Black & Veatch - 9

10. Low Solution Effort High Long Near Challenge Timeframe Black & Veatch - 10

11. Challenge Timeframe: Near Term Solution Effort: Low Challenge Timeframe: Long Term Solution Effort: Low Challenge Timeframe: Near Term Solution Effort: High Challenge Timeframe: Long Term Solution Effort: High Low Solution Effort High Long Near Challenge Timeframe Black & Veatch - 11

12. Challenge Timeframe: Near Term Solution Effort: Low Challenge Timeframe: Long Term Solution Effort: Low Challenge Timeframe: Near Term Solution Effort: High Challenge Timeframe: Long Term Solution Effort: High Matrix Definitions • Challenge Timeframe • Near term – issue is apparent, or will be, within 1 year • Long term – issue will be apparent in more than 1 year • Solution Effort • Low – cost, difficulty, and implementation timeframe for possible solution is low • High – cost, difficulty, and implementation timeframe for possible solution is high Black & Veatch - 12

13. CHALLENGE: Near SOLUTION EFFORT: Low • Siting: Identifying low cost interconnection sites • Regulatory: Cost recovery & allocation mechanisms • Process: Lack of clarity between FERC and PUC jurisdiction • Process: Time consuming and costly interconnection procedures • Process: High volume of interconnection applications • Process: New developers unfamiliar with procedures • Protection: Coordination of PV systems with existing distribution system • Voltage Regulation: PV systems affect grid voltage Black & Veatch - 13

14. ? ? ? ? ? ? ? ? ? ? CHALLENGE: NearSOLUTION EFFORT: Low • Siting: Identifying sites with low interconnection costs may be difficult for developers because they do not have sufficient information from utilities Black & Veatch - 14

15. CHALLENGE: NearSOLUTION EFFORT: Low • Regulatory: The process for allocating and recovering cost is not necessarily defined. ? ? ? ? ? ? Black & Veatch - 15

16. CHALLENGE: NearSOLUTION EFFORT: Low • Process:Lack of clarity between FERC and PUC jurisdiction • Process: Time consuming and costly interconnection procedures Black & Veatch - 16

17. CHALLENGE: NearSOLUTION EFFORT: Low • Process: High volume of interconnection applications may overwhelm utilities • Process:Barriers to entry are low leading to many new developers entering the market. There may be a lack of understanding of issues for all parties Black & Veatch - 17

18. CHALLENGE: NearSOLUTION EFFORT: Low • Protection:System protection schemes must coordinate DG with existing distribution system – reverse power flow Source: NREL Photovoltaic Systems Interconnected onto Secondary Network Distribution Systems Black & Veatch - 18

19. CHALLENGE: NearSOLUTION EFFORT: Low • Voltage Regulation: Passing cloud cover affects grid voltage, potentially triggering protection devices and impacting system operation. Source: Electrical Impact of Photovoltaic Plant in Distributed Network, by Canova, Giaccone, Spertino & Tartaglia Black & Veatch - 19

20. CHALLENGE: NearSOLUTION EFFORT: Low to High • Siting: Clustering of suitable PV sites. • Integration: PV generation is intermittent • Market: Lack of market penetration model* • Siting: Location of PV sites not known* *High effort Black & Veatch - 20

21. CHALLENGE: NearSOLUTION EFFORT: Low to High • Siting: Large rooftops suitable for PV are often located in clusters which could limit their development Black & Veatch - 21

22. CHALLENGE: NearSOLUTION EFFORT: Low to High • Integration: PV generation is intermittent and non-dispatchable Black & Veatch - 22 Image Source: Harmonic Response of Distributed Grid Connected Photovoltaic Systems by Patsalides, Stavrou, Makrides, Efthimiou & Georghiou

23. CHALLENGE: NearSOLUTION EFFORT: High • Market: Market penetration model for PV does not exist, which impacts utilities and California planning processes. • Siting: Spatial distribution of potential PV installations, especially larger ones, is unknown. Black & Veatch - 23

24. CHALLENGE: LongSOLUTION EFFORT: Low • Standards: Inverter specifications and standards could be improved • Integration: Need for monitoring & control of PV systems • Power Quality: Inverters outputting harmonics • Power Quality: Inverters Outputting incremental DC components Black & Veatch - 24

25. CHALLENGE: LongSOLUTION EFFORT: Low • Standards: Inverter specifications and standards could be improved • Integration:High penetrations ofsolar may necessitate monitoring and control of PV systems Black & Veatch - 25 Image Source: Strategic Value Analysis for Integrating Renewable Technologies in Meeting Target Renewable Penetration, CEC

26. CHALLENGE: LongSOLUTION EFFORT: Low • Power Quality: Inverters may inject harmonics into the grid reducing the power quality • Power Quality: Injection of DC component on the AC network could impact power quality Black & Veatch - 26 Image Source: Influence of Power Contribution of a Grid-Connected Photovoltaic System & its Operational Particularities, by Macedo, Zilles

27. CHALLENGE: Long; SOLUTION EFFORT: High • Integration: Forecasting solar may be necessary. • Modeling: Lack of accepted models for PV generation on the distribution system. • Modeling: Lack of insolation data showing real-world conditions Black & Veatch - 27

28. CHALLENGE: Long; SOLUTION: High • Integration: Forecasting solar resource may be necessary to control overall system. • Modeling: There is a lack of appropriate weather data, which inhibits analysis of real-world insolation conditions and system response. • Modeling: There is a lack of accepted or vetted equipment models to simulate large amounts of PV generation on the distribution system. Source: GE PSLF (http://www.turnkeymasters.com/bpa/tools.html) Black & Veatch - 28

29. Challenges This Work Group Probably Won’t be able to Address • Operational: Each utility has different operating philosophies, loading protocols, etc, which makes it difficult for developers to implement projects across the state. • Market: The availability of qualified installers or certified equipment may create a bottleneck and slow installations or cause other problems. Black & Veatch - 29

30. Possible Solutions: Intermittency, Dispatchability • Energy Storage • Curtailing Generation • Forecasting Solar Source: Solar Energy Grid Integration Systems, DOE EERE, Sandia National Laboratories Black & Veatch - 30

31. Possible Solutions: Siting, Process, Regulatory, Other • Increase Information Available to Developers on Preferred Interconnection Locations • Institute a First Pass / Fatal Flaw Interconnection Application • Update Inverter Standards Black & Veatch - 31

32. Possible Solutions: System Operation • Dedicated Feeder • Cluster Systems – Develop “Solar Grid Overlay” • Load Tap Changers, more Capacitor Banks • Low Voltage Ride Through • Smart Grid • Monitoring and Control • Re-Sectionalizing • Load Control Black & Veatch - 32