Recent Advances in Solar Resource Assessments2016/09/18 20. Zambia measurements: comparison with Solargis Bias (systematic deviation): GHI: 6.5% DIN: 16.9%. Latest Generation Satellite

Recent Advances in Solar Resource Assessments

Mr Riaan MeyerManaging Director, GeoSUN Africa

CONTENT

1. Solar Resource Assessment

2. Typical approach

3. Recent advances

4. The future

3

GeoSUN Africa in one page…

PROSPECT CONSTRUCT OPERATE

Design and supply of SCADAweather stations

Solar Maps & DataGround MeasurementsYield Reports

Calibration, inspection and testing services

Solar Resource Assessment

Solar Resource Assessment

1 Traditional Approach

Thermopile Pyranometer

Silicon (Photo-electric) Pyranometer

Ground Measurements

Pyranometer SelectionSecond Class, uncertainty < 10% (daily), <20% (hourly)

Secondary Standard, uncertainty < 2% (daily). <3% (hourly)

DateMeasured GHI

[kWh/d)

2014/03/10 00:00 0

2014/03/10 01:00 0

2014/03/10 02:00 0

2014/03/10 03:00 0

2014/03/10 04:00 0

2014/03/10 05:00 0

2014/03/10 06:00 0

2014/03/10 07:00 23

2014/03/10 08:00 215

2014/03/10 09:00 460

2014/03/10 10:00 679

2014/03/10 11:00 852

2014/03/10 12:00 959

2014/03/10 13:00 1003

2014/03/10 14:00 977

2014/03/10 15:00 878

2014/03/10 16:00 706

2014/03/10 17:00 491

2014/03/10 18:00 246

2014/03/10 19:00 36

2014/03/10 20:00 0

2014/03/10 21:00 0

2014/03/10 22:00 0

2014/03/10 23:00 0

Satellite Derived Solar Data

Top View

Side View

Orbiting SatellitesGeostationary Satellite

10

11

Scattering and absorption (ca. 15%)

Absorption (ca. 1%)

Scatter and Absorption

( ca. 15%, max. 100%)

Reflection, Scatter, Absorption (max. 100%)

Absorption (ca. 15%)

Ozone.……….…....

Aerosol…….………..…..

Water Vapor……...………

Clouds………….………..

Air molecules..……

Radiation at the top

of atmosphere

Aerosol Optical Depth(AOD) 125 km (6 hours)

Water vapour 35 km (6 h)

Satellite Derived data – how does it work? 12

Satellite Derived Maps – 110 x 90 km

Satellite Derived Maps – 40 x 40 km

1. text

2538

2490

23732405

2482

2420 2416 2385

2461

26042566

2647

2434

2686

2508 2484

2412

2495 2489

2200

2250

2300

2350

2400

2450

2500

2550

2600

2650

2700

2750

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

Aver

age

DN

I [(k

Wh

/m2/a

]

0

1

2

3

4

5

6

7

8

9

10

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

kWh

/m2/d

ay

DNI Min DNI Max DNI Average (1994 - 2011)

DateMeasured GHI

[kWh/d)SolarGIS GHI

[kWh/d]

2014/03/10 00:00 0 0

2014/03/10 01:00 0 0

2014/03/10 02:00 0 0

2014/03/10 03:00 0 0

2014/03/10 04:00 0 0

2014/03/10 05:00 0 0

2014/03/10 06:00 0 0

2014/03/10 07:00 23 13

2014/03/10 08:00 215 185

2014/03/10 09:00 460 423

2014/03/10 10:00 679 648

2014/03/10 11:00 852 832

2014/03/10 12:00 959 955

2014/03/10 13:00 1003 1004

2014/03/10 14:00 977 977

2014/03/10 15:00 878 874

2014/03/10 16:00 706 707

2014/03/10 17:00 491 493

2014/03/10 18:00 246 257

2014/03/10 19:00 36 46

2014/03/10 20:00 0 0

2014/03/10 21:00 0 0

2014/03/10 22:00 0 0

2014/03/10 23:00 0 0

Satellite

Derived

Data

Date/Time GHI Ground [kWh/m2]

2012/11/03 05:00 0

2012/11/03 06:00 0

2012/11/03 07:00 16

2012/11/03 08:00 186

2012/11/03 09:00 431

2012/11/03 10:00 669

2012/11/03 11:00 866

2012/11/03 12:00 1012

2012/11/03 13:00 1087

2012/11/03 14:00 1085

2012/11/03 15:00 1028

2012/11/03 16:00 896

2012/11/03 17:00 702

2012/11/03 18:00 421

2012/11/03 19:00 209

2012/11/03 20:00 29

2012/11/03 21:00 0

2012/11/03 22:00 0

0

200

400

600

800

1000

1200

03

:00

:00

04

:00

:00

05

:00

:00

06

:00

:00

07

:00

:00

08

:00

:00

09

:00

:00

10

:00

:00

11

:00

:00

12

:00

:00

13

:00

:00

14

:00

:00

15

:00

:00

16

:00

:00

17

:00

:00

18

:00

:00

19

:00

:00

20

:00

:00

21

:00

:00

22

:00

:00

DNI Ground [kWh/m2]

(Uncertainty of hourly values)

GHI – 12% to 45%

DNI – higher than GHIGHI – 4% to 8%

DNI – 8% to 15%(Uncertainty of annual values)

17

Satellite Derived vs Measured

Data

2

3

4

5

6

1-J

un

-11

4-J

un

-11

7-J

un

-11

10

-Ju

n-1

1

13

-Ju

n-1

1

16

-Ju

n-1

1

19

-Ju

n-1

1

22

-Ju

n-1

1

25

-Ju

n-1

1

28

-Ju

n-1

1

GH

I -d

aily

to

tal [

kWh

/m2 /

day

]

GHI - Satellite HC-3 GHI - Ground measured GHI - Satellite SGIS

0

2

4

6

8

10

1-N

ov-

11

3-N

ov-

11

5-N

ov-

11

7-N

ov-

11

9-N

ov-

11

11

-No

v-1

1

13

-No

v-1

1

15

-No

v-1

1

17

-No

v-1

1

19

-No

v-1

1

21

-No

v-1

1

23

-No

v-1

1

25

-No

v-1

1

27

-No

v-1

1

29

-No

v-1

1

GH

I -d

aily

to

tal [

kWh

/m2 /

day

]

GHI - Ground measured GHI - SolarGIS

HC-3 Satellite

Derived vsMeasured

Data

0.0

2.5

5.0

7.5

10.0

12.5

15.0

1-F

eb

-11

4-F

eb

-11

7-F

eb

-11

10

-Fe

b-1

1

13

-Fe

b-1

1

16

-Fe

b-1

1

19

-Fe

b-1

1

22

-Fe

b-1

1

25

-Fe

b-1

1

28

-Fe

b-1

1

DN

I -

dai

ly t

ota

l [kW

h/m

2 /d

ay]

DNI - Ground measured DNI - Satellite

0.0

2.5

5.0

7.5

10.0

12.5

15.0

1-M

ay-1

1

4-M

ay-1

1

7-M

ay-1

1

10

-May

-11

13

-May

-11

16

-May

-11

19

-May

-11

22

-May

-11

25

-May

-11

28

-May

-11

31

-May

-11

DN

I -

dai

ly t

ota

l [kW

h/m

2 /d

ay]

DNI - Ground measured DNI - Satellite

Broken Clouds

2016/09/18 20

Zambia measurements: comparison with Solargis

Bias (systematic deviation):GHI: 6.5%DIN: 16.9%

Latest GenerationSatellite Derived

Thank you / AsanteContact DetailsMr Riaan Meyer, MD, 084 876 4816Unit 1, CS Africa building, 1 Meson street Technopark, Stellenbosch, 7600, South [email protected] www.geosun.co.za

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