Big Wind Study

Technical Committee MeetingJanuary 27, 2012

Outline

1.Impacts of INC and DEC wind reserves on hydro generating capability

2.Impacts of increasing wind capacity on hydro and thermal dispatch

3.Impacts of increasing wind capacity on the existing over generation problem

4.Assessing the load carrying capability for wind

January 27, 2012

Effects of INC and DEC Reserves on Hydroelectric Capability

INC Reserve – Covers peak load when wind doesn’t blow

DEC Reserve – Backs off generation during light load hours when wind does blow

January 27, 2012

Effects of INC and DEC Reserveson Hydroelectric Capability

0 2 4 6 8 10 12 148000

16000

24000

32000Origw/DECw/INC + DEC

Hour of Day

Meg

awatt

s

DEC and INC both tend to flat-

tenhydro generating

capability

January 27, 2012

DEC Reduces Hydro Peaking Capability(for 6K of installed wind)

Period 2-Hr 4-Hr 6-Hr 8-Hr 10-Hr 12-HrSep -33 -444 -699 -778 -742 -612Oct -364 -976 -1115 -1065 -865 -636Nov -2 -108 -354 -351 -356 -322Dec -19 -149 -404 -387 -365 -325Jan -64 -186 -406 -407 -393 -341Feb -192 -274 -512 -509 -472 -416Mar -54 -142 -479 -501 -465 -424

Apr 1 -855 -1083 -1057 -928 -778 -597Apr 2 -319 -349 -380 -357 -319 -304May 0 0 -8 -57 -84 -92Jun -114 -233 -373 -432 -434 -377Jul 0 -41 -169 -255 -321 -318

Aug 1 0 0 -36 -149 -295 -316Aug 2 -227 -652 -951 -942 -820 -669

January 27, 2012

For Illustration Only

DEC Increases Minimum Hydro Generation

January 27, 2012

1 27 53 79 1051311571832092352612873133393653914174434694955215475735996256516777037290

5000

10000

15000

20000

25000Simulated dispatch for a very wet year

Hydro Thermal Wind

Hour of the Month

Meg

awatt

s

For Illustration Only

Hit minimum hydro generation often

Effects on Resource Dispatch

January 27, 2012

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70

0

5000

10000

15000

20000

25000Simulated Dispatch – No Wind

Demand Therm - No Wind Hydro - No Wind

Hours in the Month

Meg

awatt

s

January 27, 2012

For Illustration Only

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70

0

5000

10000

15000

20000

25000Simulated Dispatch – 3K Wind

Demand Therm - 3K Wind Hydro - 3K Wind Wind - 3K

Hours in the Month

Meg

awatt

s

Thermal absorbs the “energy” component while hydro ab-sorbs the hourly variation

January 27, 2012

For Illustration Only

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70

0

5000

10000

15000

20000

25000Simulated Dispatch – 6K Wind

Demand Therm - 6K Wind Hydro - 6K Wind Wind - 6K

Hours in the Month

Meg

awatt

s

Thermal is OFF

Hydro hits min

January 27, 2012

For Illustration Only

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70

6000

8000

10000

12000

14000

16000

18000Simulated Dispatch – Hydro Only

Hydro - No Wind Hydro - 3K Wind Hydro - 6K Wind

Hours in the Month

Meg

awatt

sMore hourly variation in hydro generation

January 27, 2012

For Illustration Only

Adequacy Tech Meeting

Future work

• Identify resources whose dispatch is most affected by increasing wind capacity

• Quantify how natural gas use decreases with increasing amounts of wind

• Investigate how thermal ramp-ups and ramp-downs change with increasing wind

• Should we investigate carrying some INC and DEC requirements with thermal resources?

• Anything else?January 27, 2012

Oversupply Problem*

January 27, 2012

Oversupply conditions occur when the minimum system generation exceeds firm load and secondary sales markets.

*Still working with BPA staff to review results.

0 1 2 3 4 5 6 7 8 90

500

1000

1500

2000

2500

3000

Jul

JunMay

Apr

MarFeb

Oversupply in Average Megawatts(averaged over all hours of the month)

Installed Wind (GW)

Ove

rsup

ply

(MW

-Mo)

Problem occurs even with no wind

For Illustration Only

No sales market assumed in this case

January 27, 2012

For Illustration Only

January 27, 2012

Intertie size

Assessing the Effective Load Carrying Capability of Wind (ELCC)

January 27, 2012

What is ELCC?• “Effective load carrying capability” is defined as

the amount of incremental load a resource can serve without degrading adequacy.

• It is usually expressed as a percentage of a resource’s capacity.

• Example: a standalone CT with 5% FOR and infinite fuel supply has an ELCC of 95%

• ELCC is a function of the system the new resource is added to – this is particularly important for wind.

January 27, 2012

Study Methodology

• Base case– Remove all wind– Calculate total annual average curtailment

• Study cases– Add 200 MWa of annual shaped load– Add increments of wind capacity until the total

annual average curtailment equals that in the base– Repeat above with greater amounts of load

January 27, 2012

ELCC Results (+200 MWa load)

15% 20% 25% 30% 35% 40% 45%1200000

1250000

1300000

1350000

1400000

Average Load/Wind Capacity (%)

Tota

l Avg

Cur

tailm

ent (

MW

-hrs

)

Base Case

200 MWa Load, 500 MW Wind

200 MWa Load, 1000 MW Wind

ELCC = 26.4%

January 27, 2012For Illustration Only

Annual Wind ELCC Results

0 1000 2000 3000 4000 5000 6000 7000 8000 90000%

5%

10%

15%

20%

25%

30%

AverageIncremental

Installed Wind Capacity (MW)

Win

d EL

CC (%

)

January 27, 2012

For Illustration Only

Observations• ELCC declines with increasing amounts of wind

because system flexibility is used up• Eventually wind ELCC will flatten out• Average annual wind generation is ~ 30%, yet

currently aggregate ELCC is ~ 23%Thus, can’t plan on average wind generation

• Adding storage will increase ELCC• Adding more diverse wind generation will also

increase aggregate ELCC

January 27, 2012