Wind Integration and Grid Reliability Impacts

Charlton I. Clark Technology Manager, Renewable Systems Interconnection

Wind and Water Power Program Office of Energy Efficiency and Renewable Energy U. S. Department of Energy

NERC RICCI Task Force-July 17, 2009

Outline

• Overview of wind integration studies– Past studies– Western Wind and Solar Integration Study

(WWSIS)– Eastern Wind Integration and Transmission

Study (EWITS)• Initial reliability results

Past/Ongoing Utility Integration Studies

•Multiple integration studies conducted for various utilities•Previous studies evaluated a single utility control area•Primary focus related to integration costs to the host utility

Current Large Scale Integration Studies

• Integration study footprints expanding– WWSIS =>

WestConnect Footprint

– EWITS => Eastern Interconnection (except FRCC)

WWSIS Overview

• Goal – To understand the costs and operating

impacts due to the variability and uncertainty of wind, PV and concentrating solar power (CSP) on the WestConnect grid

– Not the cost of wind or solar generation• Scope of study

– Operations, not transmission study– Study year – 2017 to line up with

WECC studies– Simulate load and climate of 2004,

2005, 2006 forecast to 2017

5

WWSIS Scenario Overview

• Baseline – no new renewables• In-Area – each transmission area meets its target from sources

within that area– 30% wind, 5% solar in footprint (20% wind, 3% solar in the rest of WECC)– 20% wind, 3% solar (10% wind, 1% solar rest of WECC)– 10% wind, 1% solar (10% wind, 1% solar rest of WECC)

• Mega Project – concentrated projects in best resource areas• Local Priority – Balance of best resource and in-area sites• Plus other scenarios yet to be determined (high solar, high

capacity value, high geographic diversity)Solar is 70% CSP and 30% distributed PV. CSP has 6 hours of thermal storage. Penetrations

are by energy.

6

Benefits of geographic diversity: Actual wind output vs. One- Hour delta as a Percentage of Installed Wind Capacity (30% In-Area Scenario) New Mexico (2006)

Study area aggregation tends to mitigate relative impact of large ramps

7

-8000

-6000

-4000

-2000

0

2000

4000

6000

8000

-5000 -4000 -3000 -2000 -1000 0 1000 2000 3000 4000 5000

Load Delta (MW)

Win

d De

lta (M

W) (

30%

Sce

nario

)

FallWinterSpringSummer

Wind Deltas vs Load Deltas by season for 2004-2006 (30% in Area Scenario)

(1199, -5926)

(-4125, 2950)

Increased L-W up-ramps

Increased L-W down-ramps Load and wind

deltas offset

Load and Wind deltas offset

Q1

Q2

Q4Q3

(2985, -4372)

-7000 MW

-6000 MW

-5000 MW

-5000 MW

-6000 MW

-7000 MW

(186, 7528)

8

Summary Statistics (hourly variability)

9

Summary Stats - ten-minute variability

10

Study Area Total Load, Wind and Solar Variation Over Month of April (30% in Area Scenario)

Substantial increase in net load variability driven largely by wind variation

-5000

0

5000

10000

15000

20000

25000

30000

35000

1-Apr 8-Apr 15-Apr 22-Apr 29-Apr

Day

MW

Ld(Base)

Wd(30%)

PV(30%)

CSP(30%)

L-W-S(30%)

Minimum net load: –2887 MWInstantaneous penetration: 112%

11

Study Area Total Load, Wind and Solar Variation Over Month of April (30% in Area Scenario)

Four EWITS Scenario Overview• Scenario 1, 20% wind penetration – “Lowest Cost

Wind”: Utilizes high quality wind resources in the Great Plans, with other development in the east where good wind resources exist.

• Scenario 2, 20% wind penetration – “Hybrid, with Offshore”: Some wind generation in the Great Plains is moved east, with capacity increased in PJM, NYISO, and ISO-NE.

• Scenario 3, 20% wind penetration – “Load-weighted (local) Wind Development, Aggressive Offshore”: More wind is moved east toward load centers, necessitating even more utilization of off-shore resources.

• Scenario 4, 30% wind penetration – “Aggressive On- and Off-shore”. Meeting the 30% energy penetration level uses a substantial amount of the higher quality wind resource. Lots of offshore is needed to reach the target energy level.

Region Onshore (MW) Offshore (MW) Total (MW)MISP/MAPP 94,808                       ‐                                  94,808                      

SPP 91,843                       ‐                                  91,843                      TVA 1,247                         ‐                                  1,247                        SERC 1,009                         ‐                                  1,009                        

PJM ISO 22,669                       ‐                                  22,669                      NYISO 7,742                         ‐                                  7,742                        ISO‐NE 4,291                         ‐                                  4,291                        

Total 223,609                     ‐                                  223,609                    

Region Onshore (MW) Offshore (MW) Total (MW)MISO/MAPP 69,444                       ‐                                  69,444                      

SPP 86,666                       ‐                                  86,666                      TVA 1,247                         ‐                                  1,247                        SERC 1,009                         4,000                         5,009                        

PJM ISO 28,192                       5,000                         33,192                      NYISO 13,887                       2,620                         16,507                      ISO‐NE 8,837                         5,000                         13,837                      

Total 209,282                     16,620                       225,902                    

Region Onshore (MW) Offshore (MW) Total (MW)MISO/MAPP 46,255                       ‐                                  46,255                      

SPP 50,958                       ‐                                  50,958                      TVA 1,247                         ‐                                  1,247                        SERC 1,009                         11,040                       12,049                      

PJM ISO 38,956                       9,280                         48,236                      NYISO 13,887                       39,780                       53,667                      ISO‐NE 13,887                       4,000                         17,887                      

Total 166,199                     64,100                       230,299                    

Region Onshore (MW) Offshore (MW) Total (MW)MISO/MAPP 95,046                       ‐                                  95,046                      

SPP 94,576                       ‐                                  94,576                      TVA 1,247                         ‐                                  1,247                        SERC 1,009                         11,040                       12,049                      

PJM ISO 38,956                       9,280                         48,236                      NYISO 13,887                       54,780                       68,667                      ISO‐NE 13,887                       4,000                         17,887                      Total 258,608                     79,100                       337,708                    

Geographic Diversity of Wind

Annual Average Incremental Variable Spinning reserve (MW)

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

Region

Varia

ble

Res

erve

(MW

)

IDEAL WINDACTUAL WIND S1ACTUAL WIND S2ACTUAL WIND S3ACTUAL WIND S4

IDEAL WIND 885 43 514 1,055 217 202 365 741

ACTUAL WIND S1 4,424 1,020 6,308 1,994 618 399 420 816

ACTUAL WIND S2 3,245 835 6,176 2,359 1,118 1,046 418 955

ACTUAL WIND S3 2,419 503 3,695 4,463 1,614 1,789 418 955

ACTUAL WIND S4 4,423 1,038 6,487 5,410 1,614 1,789 418 955

MISO MAPP SPP PJM NYISO ISO-NE TVA SERC

Questions??

• http://wind.nrel.gov/public/WWIS/• http://wind.nrel.gov/public/EWITS/

Charlton.clark@ee.doe.gov202-586-8040