K E M A T & D C O N S U L T I N G Power System Conference, Clemson, South Carolina, March 8-11, 2005 Principles and Issues Relating to the Interconnection of Wind Power Zhenyu Fan & Johan Enslin KEMA T&D CONSULTING 3801 Lake Boone Trail, Suit 200 Raleigh, NC 27607

K E M A T & D C O N S U L T I N G 2 Overview: n Study Background n Key Issues n Objectives & Scope n Case Studies n Summary

K E M A T & D C O N S U L T I N G 3 Source: AWEA’s Global Market Report 1.Germany: 12,001 MW 2.Spain: 4830 MW 3.US: 4275 MW 4.Denmark: 2880 MW 5.India: 1702 MW Wind Power is growing!

K E M A T & D C O N S U L T I N G 4 Table 1: Example of wind systems and installed penetration levels RegionPeak Load MW Installed Wind MW Penetration Denmark 5,0003,10062% Germany 77,00014,60019% Spain 36,0006,20017 % The Netherlands 14,0001,0007% Continental USA 808,0006,7400.8% Texas 63,0001,2882% New Mexico 1, %

K E M A T & D C O N S U L T I N G 5 Wind Resource in the USA

K E M A T & D C O N S U L T I N G 6 Wind Power installed in US

K E M A T & D C O N S U L T I N G 7 Wind Power Interconnection Studies n Interconnection procedures are not uniform n In general, interconnection procedures require:  to apply for a queue position;  system feasibility, system impact, and facilities studies;  interconnection and construction agreements;  construction of interconnection facilities, and network upgrades if required. n FERC governs the generation interconnection process

K E M A T & D C O N S U L T I N G 8 Interconnected Issues: Power Flow Short Circuit Transient Stability Electromagnetic Transient

K E M A T & D C O N S U L T I N G 9 Protection Power Leveling and Energy Balancing Power Quality Interconnected Issues (Cont.):

K E M A T & D C O N S U L T I N G 10 Network Interface Options A – Direct link, no compensation B – SVC, reactive power, voltage C – STATCOM, added power quality D – STATCOM with battery, added power balance, trading, UPS, Black-start, etc.

K E M A T & D C O N S U L T I N G 11 Case Studies:  California ISO System  Dutch Project

K E M A T & D C O N S U L T I N G 12 California ISO System: n CA Wind Resources  Areas designated "Good" are roughly equivalent to an estimated mean annual power at 10 meter height of 200 Watts/square meter to 300 W/m 2 and "Excellent" to above 300 W/M 2.  In the year 2000, wind energy in California produced 3,604 million kilowatt-hours of electricity, about 1.27 percent of the state's total electricity. That's more than enough to light a city the size of San Francisco.

K E M A T & D C O N S U L T I N G 13 California ISO System: n CA Electricity Market  The CA ISO 2004 Summer peak load is 44,422 MW with a minimum projected planning reserve of 16.4% and a corresponding operating reserve of 2,750 MW. Approximately 32,700 MW are thermal units, 2,600 MW are wind with the remaining 18,700 MW consisting of a mix of hydro, pumped storage and solar.  The 2004 base scenario forecast wind capacity for California during summer peaks is only 235 MW (9.0% of the installed wind capacity).

K E M A T & D C O N S U L T I N G 14 Wind Power Operating Reserve and Regulation Impact n Load forecasting error affects operating reserves while short- term fluctuations in load affect regulation n Forecasting errors should be considered in combination n Geographical dispersion of wind resources tend to reduce the amount of incremental load following requirements

K E M A T & D C O N S U L T I N G 15 Wind Power Impact on Reliability and System Operation n Hydro-power resources can be used for power balancing wind power plants, n Thermal units on the system would still be used for operating reserves. n System reliability and load following capability will not be affected significantly by the addition of a significant amount of wind generation.

K E M A T & D C O N S U L T I N G 16 Wind Power Impact on Generation n The decision to build a wind plant depends on many factors. n Capacity factor of CA ISO is 9% on an annual basis, new wind project are likely to have capacity factors in the 35-40% range. n The addition of large amounts of wind generation to a system would have some economic and physical impact on merchant plants in the medium to long run.

K E M A T & D C O N S U L T I N G 17 Major Dutch HV Network Upgrades for interconnection of a 6,000 MW offshore wind park in the North Sea Netherlands Project

K E M A T & D C O N S U L T I N G 18 Offshore Wind Energy In Netherlands n 12% of energy within EU should be provided by renewables by the year 2010, with a possible installed wind capacity of at least 40 GW n 6000 MW by 2020 wind power studies n An energy storage system integrated with high power electronics can mitigate interconnection problems

K E M A T & D C O N S U L T I N G 19 Storage Options for 6 GW Wind Farm n Based on Flow-battery technology  6,000 M€, 30 years NPV, 1x1 km size n Not feasible by factor 10 as a single solution VSC Interface

K E M A T & D C O N S U L T I N G 20 Energy Storage n A 2500 MW battery plant will be required n Total capacity is 62 GWh n Based on the difference between low and high APX-values, the profits of the reduction of the number of start/stops, and avoiding the investment cost of the stabilization system, and avoiding of the unbalance cost, the project becomes feasible. n In this case, a seven- to eight-year break-even can be achieved,

K E M A T & D C O N S U L T I N G 21 Summary n Large-scale wind park requires a different integration approach from those used for smaller wind farms. n Mitigation devices are needed for the interconnection issues with distributed power n Key technologies can minimize the impact on the network n Several functions should be integrated into the functionality of the energy storage system

K E M A T & D C O N S U L T I N G 22 Thank You !