Presented by:

LUIS MARTÍN POMARES

ENERGY DEPARTAMENTRenewable energy division

5rd Experts Meeting of the IEA SHC Task “Solar Resource Knowledge Management”

&MESoR Meeting

Wels, Austria9 – 11 June 2008

Global solar radiation forecasting with non-lineal statistical techniques and qualitative predictions

from Spanish National Weather Service

2

OUTLOOK

1. TIME SERIES GLOBAL SOLAR RADIATION HALF DAILY PROPERTIES

2. CLEARNESS INDEX PREDICTIONS

3. LOST COMPONENT PREDICTIONS

4. LOST COMPONENT + QUALITATIVE PREDICTIONS

5. CONCLUSIONS

3

TIME SERIES GLOBAL SOLAR RADIATION HALF DAILY PROPERTIES

Global solar irradiance half daily time series :

Removing stationarity from time series: Using clearness index. Using lost component variable. Subtracting each value mean value of 2d+1 days. Removing from time series anual armonic (first armonic from

fourier analysis). If the time series obtained is not stationary a good

way to achieve so is differencing consecutive days.

Non StationaryNon Gaussian DataNon Linear

Data Preprocessing

4

Madrid RRN AEMet

Murcia RRN AEMet

2.5

W 0.0

CLEARNESS INDEX HALF DAILY PREDICTIONS

MADRID RRN AEMet MURCIA RRN AEMet

1 2 3 4 5 66

8

10

12

14

16

18

20

22

24

Horizonte Predicción (Semidías)

Mej

ora

% R

MSD

Madrid: Mejora frente Persistencia

MS(2)-AR(1)/PersistenciaNN(10)/PersistenciaANFIS(6)/Persistencia

1 2 3 4 5 66

8

10

12

14

16

18

20

22

24

Horizonte Predicción (Semidías)

Murcia: Mejora frente Persistencia

MS(2)-AR(1)/PersistenciaNN(10)/PersistenciaANFIS(6)/Persistencia

CIES2008, June 17-21,2008, Vigo (Spain)

IMPROVEMENT OVER PERSISTENCE IN TERMS OF %RMSDmod1 el

persistence

ierrorimprovement

ierror

5

CLEARNESS INDEX HALF DAILY PREDICTIONS

1 2 3 4 5 622

24

26

28

30

32

34

36

38

40

Horizonte Predicción (Semidías)

%RM

SD P

redi

cció

n Se

mid

iaria

Kt

NN(1)NN(2)NN(3)NN(4)NN(5)NN(6)NN(7)NN(8)NN(9)NN(10)PER

MADRID RRN AEMet MURCIA RRN AEMet

1 2 3 4 5 622

24

26

28

30

32

34

36

38

40

Horizonte Predicción (Semidías)

NN(1)NN(2)NN(3)NN(4)NN(5)NN(6)NN(7)NN(8)NN(9)NN(10)PER

CIES2008, June 17-21,2008, Vigo (Spain)

RMSD FOR BEST MODEL: NN(10)

6

CLEARNESS INDEX HALF DAILY PREDICTIONS

CIES2008, June 17-21,2008, Vigo (Spain)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

KT Semidiario Observado

KT

Se

mid

iari

o P

rev

isto

0 0.2 0.4 0.6 0.8 10

1

2

3

4

5

6

Kt Semidiario

7

LOST COMPONENT PREDICTIONS

EUROSUN2008, October 7-10, Lisbon (Portugal)

0 100 200 300 400 500 600 7000

1000

2000

3000

4000

5000

6000

Half Day

Wm

-2

Differencing day by day

8

LOST COMPONENT PREDICTIONS

EUROSUN2008, October 7-10, Lisbon (Portugal)

Differencies

0 100 200 300 400 500 600 700500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Half Day

Lo

st C

om

po

nen

t W

m-2

9

LOST COMPONENT PREDICTIONS

EUROSUN2008, October 7-10, Lisbon (Portugal)

0 100 200 300 400 500 600 700-3000

-2000

-1000

0

1000

2000

3000

Half Day

Dif

f L

ost

Co

mp

on

ent

Wm

-2

-4000 -3000 -2000 -1000 0 1000 2000 3000 40000

0.5

1

1.5x 10-3

Num

ber o

f Sam

ples

Diff Lost Component

10

LOST COMPONENT PREDICTIONS

MADRID RRN AEMet MURCIA RRN AEMet

1 2 3 4 5 622

24

26

28

30

32

34

36

38

40

Prediction Horizon Half Daily

%R

MS

D

1 2 3 4 5 620

22

24

26

28

30

32

34

36

38

40

Prediction Horizon Half Daily

NN(1)NN(2)

NN(3)

NN(4)

NN(5)

NN(6)NN(7)

NN(8)

NN(9)

NN(10)Persistencia

11

LOST COMPONENT PREDICTIONS

MADRID RRN AEMet

1 2 3 4 5 66

8

10

12

14

16

18

20

22

24

Horizonte Predicción (Semidías)

Mej

ora

% R

MSD

Madrid: Mejora frente Persistencia

MS(2)-AR(1)/PersistenciaNN(10)/PersistenciaANFIS(6)/Persistencia

CIES2008, June 17-21,2008, Vigo (Spain)

IMPROVEMENT OVER PERSISTENCE IN TERMS OF %RMSD

1 2 3 4 5 60.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0.22

0.24

0.26

0.28

0.3

Prediction Horizon

Impr

ovem

ent %

RMSE

NN/PER

12

LOST COMPONENT PREDICTIONS

MURCIA RRN AEMet

1 2 3 4 5 66

8

10

12

14

16

18

20

22

24

Horizonte Predicción (Semidías)

Murcia: Mejora frente Persistencia

MS(2)-AR(1)/PersistenciaNN(10)/PersistenciaANFIS(6)/Persistencia

CIES2008, June 17-21,2008, Vigo (Spain)

IMPROVEMENT OVER PERSISTENCE IN TERMS OF %RMSD

1 2 3 4 5 60.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0.22

0.24

0.26

0.28

0.3

Horizon Prediction Half Daily

Impr

ovem

ent %

RM

SD

NN/PER

13

LOST COMPONENT PREDICTIONS

EUROSUN2008, October 7-10, Lisbon (Portugal)

14

AEMet Synoptic Predictions by Site

Total Cloud CoverECMWF

HIRLAM/AEMetPROMETEOWRF/MM5….

EUROSUN2008, October 7-10, Lisbon (Portugal)

Energy Values

15

EUROSUN2008, October 7-10, Lisbon (Portugal)

LOST COMPONENT + QUALITATIVE PREDICTIONS

MADRID RRN AEMet MURCIA RRN AEMet

1 2 3 4 5 6

10

15

20

25

30

35

40

Prediction Horizon Half Daily

%R

MS

D

NN(1)NN(2)NN(3)NN(4)NN(5)NN(6)NN(7)NN(8)NN(9)NN(10)PER

1 2 3 4 5 6

10

15

20

25

30

35

40

Prediction Horizon Half Daily

%R

MS

D

16

EUROSUN2008, October 7-10, Lisbon (Portugal)

MADRID RRN AEMet MURCIA RRN AEMet

LOST COMPONENT + QUALITATIVE PREDICTIONS

1 2 3 4 5 60.6

0.62

0.64

0.66

0.68

0.7

Horizon Prediction (Half Daily)

Imp

rov

em

en

t %

RM

SD

NN(10)/PER

1 2 3 4 5 60.6

0.62

0.64

0.66

0.68

0.7

Horizon Prediction (Half Daily)

Imp

rove

men

t %

RM

SD

NN(10)/PER

17

LOST COMPONENT + QUALITATIVE PREDICTIONS

EUROSUN2008, October 7-10, Lisbon (Portugal)

18

EUROSUN2008, October 7-10, Lisbon (Portugal)

LOST COMPONENT + QUALITATIVE PREDICTIONS

MADRID RRN AEMet

1 2 3 4 5 6

10

15

20

25

30

35

40

Prediction Horizon Half Daily

%R

MS

D

1 2 3 4 5 6

10

15

20

25

30

35

40

Prediction Horizon Half Daily

%R

MS

D