Meet the New DNV GL. A Global Energy Powerhouse. Planning the Grid for Winds of Change. January 2014

Transcription

1 Meet the New DNV GL A Global Energy Powerhouse Planning the Grid for Winds of Change Mandhir Sahni, PhD, Deputy Head of Dept., Power System Planning DNV GL Energy Advisory NA January SAFER, SMARTER, GREENER

2 Planning the Grid for Winds of Change: Key Drivers Renewable Penetration & Integration CREZ Transmission Development & Renewable Integration ERCOT-proposed Ancillary Service Whitepaper System Operational Complexities Resource Adequacy Stakeholder discussions around the Houston Import (HIP) Project Transmission System Planning West Texas Load Growth & HIP Challenges Load/ Generation locational & growth diversity Dynamic Grid Conditions Evolution of the reactive power and HVRT requirements for GEs Influx of non-60hz devices Coordinated control & challenges on weaker portions of the grid Transmission System Planning, as we know it over the last two decades or so, is on the cusp of a transition: Predictive Vs Preventive Planning 2

3 Planning the Grid for Winds of Change: The Texas Challenge ERCOT at the forefront of large-scale grid integration of renewables 11,255 MW of existing wind connected to ERCOT grid (per ERCOT December 2013 ROS report) Cumulative planned wind generation expected to be close to 18.2GW (per signed IAs, December 2013 ROS report) Challenges come with the territory Transfer capability from Panhandle region to ERCOT load centres expected to be limited by voltage stability ERCOT PREZ Investigation Significant wind in relatively weaker portions of the grid pose stability & control challenges ERCOT PREZ Investigation Wind integration to a grid with numerous series compensated lines requires evaluation of Sub-Synchronous Resonance/Control Interaction issues Review of the reactive power and voltage ride through stipulations HVRT requirements currently under discussion via NOGRR-124 Dynamic reactive capability Problem that needs more definition in terms of performance boundaries 3

4 Planning the Grid for Winds of Change: The Texas Challenge ERCOT Houston Import Project (HIP) Interesting example of the changing nature of transmission planning challenges associated with an evolving grid Evaluation of system needs to support the Houston load growth while maintaining system reliability An ERCOT first in many ways Number of RPG projects submitted for consideration by ERCOT Engaging stakeholder discussion in terms of the nature of the issue transmission vs. resource adequacy Locational Dimension Houston load pocket can be fed from all three zones in EROT (North, West and South) Significant focus on long term performance of solution ERCOT has demonstrated the required flexibility in stakeholder discussion and study approach Engaging discussions across entire stakeholder community New/interesting approaches utilized by ERCOT to evaluate relative project merits 4

5 Planning the Grid for Winds of Change: The Texas Challenge West Texas Load Growth Significant load growth in West Texas owing to increase in oil drilling Historically, transmission in West Texas predominantly designed and expanded to integrate wind generation to the grid Apart from the load growth rate, nature of load growth presents interesting challenges Significantly sized spot loads Predominantly dynamic loads Concentrated loads System-wide evaluation of transmission adequacy in order to serve the expected load growth ERCOT West Texas Study Illustrative Example, FIDVR Phenomenon Concentrated and dynamic nature of the loads call for an advanced study to evaluate the following: Fault Induced Delayed Voltage Recovery (FIDVR) Dynamic reactive power adequacy and transient voltage recovery Source: Load Modeling & Control, Transmission Research Colloquium, CA, Sep,

6 Planning the Grid for Winds of Change: The Texas Challenge Dynamic Grid Conditions Constantly evolving nature of the grid calls for predictive (as opposed to preventive) system planning ERCOT witnessing some of the impacts associated with evolving nature of the transmission grid 1.1 Channel Plot Proposed High Voltage Ride Through (HVRT) requirements Interesting dynamics both from system and generation side of the fence Dynamic Reactive Power Requirements How do you define the performance boundary for dynamic VAR requirements for testing/evaluation purposes? Challenges associated with weak system conditions 0.1 Why even bother about the Short Circuit Ratio (SCR)? Small Signal Stability for large power transfer conditions Time (seconds) Before Mitigation After Mitigation 9 10 Frequency response and stability with increasing renewable penetrations To think of it, solar hasn t even really come into the picture yet! Dynamic Voltage Response Is it a VAR support or system strength issue? 6

7 Planning the Grid for Winds of Change: Pieces to the Puzzle ERCOT leading the way in terms of tackling challenges as seen in the planning horizon Ingredients for the roadmap for next generation transmission planning Transmission planning expected to span much more than steady state and dynamics Intra-Hour simulations to understand system behaviour/response in terms of AGC, frequency response, etc. Advanced power system study tools/methodologies to address complex issues Need to strike the fine balance between deterministic, stochastic and scenario-based planning approaches Grid performance dependent on the entire stakeholder community more than ever before Integration of emerging technologies, i.e. storage, solar PV, etc. Accounting for operational complexities in planning better collaboration between planning & operations Model fidelity Do we know if our models represent the response of the device in the field? Integration of PMU data to improve system planning models 7

8 Planning the Grid for Winds of Change: Pieces to the Puzzle Grid Interconnection Evaluation Processes & Timeframes Electro Magnetic Transient Simulations Stability Analysis System Protection AGC & Frequency Response Evaluations Long Term Economic Assessment Reliability Assessment 1us 1 sec 1 min 1 Hr 1 day 1 Yr PV & Storage Steady State Evaluations PV & Storage (Mid Term Analysis more critical for storage) Reliability Impact on Grid Evaluation of Interconnecting Technology Potential Benefit to Grid 8

9 Planning the Grid for Winds of Change: The DNV GL Offering Our Service Lines Market and Policy Development What Project Management Technical Services How Why Power System Planning What Operational Excellence The dynamic and unique nature of the ERCOT transmission grid brings many challenges and opportunities. The key issues including concentrated load growth, limited import capability to some of the major load centers, resource adequacy, renewable integration and emerging technologies call out for innovative transmission planning strategies. ERCOT echoed that view in its recently-published strategic plan. While much progress has been made, DNV GL's unique position as an independent advisor to utilities and ERCOT (across the entire value chain) alike allows us to see innovation potential across the stakeholder community. To realize the best results, the focus must be on finding ways to fully capture that innovation through collaboration. 9

10 DNV GL Energy assists customers in delivering a safe, reliable, efficient, and sustainable energy supply around the globe. Please contact me to learn more. Mandhir Sahni, PhD msahni@pwrsol.biz T: M: SAFER, SMARTER, GREENER 10