1

Prediction of electrical energy

by photovoltaic devices in urban situations

By. R.C. Ott

July 2011

2

General model to compute the electric output of your Solar panels

3

Find out your geographic location and sight to the celestial sphere

Where you live

4

The maximum of solar irradiation is a fixed astronomical amount and is dependend of your geographical location.

Not each place on Earth is convenient

5

Orientation of your solar panels (= angles α and β) are importantfor best performances

How about your panel azimuth and inclination ?

Detailed installation properties

6

Realize that usefull sunlight comes from any direction , but most quantity comes from DIRECT irradiation

How much Solar radiadion ?

7

Your (urban) local sky line is mostly not a straight line..

Sky obstructions limits your solar energy capacity

8

An all sky fish-eye lens as equipment to measure your local sky-line

9

Or use a drone to optimize your your panel location if the roof is difficult to enter

10This fish-eye lens can tell you more about your location

11The fish-eye photo is equidistant processed by FESA

12

… and imported to Tabulae Solis (In this case, the trees reduce you Solar panel output capacity)

Daily direct sun light over a total year

13

SOLAR PANEL CALENDAR ( REAL SKY )

DATE: 06-08-2011 TIME: 12:41:06 Alt = 0 m ; Time zone = 1:0 hour Daylight s.time

Location: North 52°06'00" ; East 5°07'00" ;

TL(AM2)/Month : 2,75 2,75 3,75 3,75 3,75 3,75 4,25 4,75 4,25 3,75 2,75 2,75

SOLAR PANEL MOUNT:

Heading = 154°45' ; Inclination = 45°00' ; Yaw = 0°00' ; Alt. =6

Date Sun-rise Sun-set Hor.Irr. Inc.Irr. Energy

-----------------------------------------------------------

02-01-2011 08:48 16:39 0,11 0,22 0,09

09-01-2011 08:46 16:48 0,13 0,28 0,11

16-01-2011 08:41 16:58 0,17 0,41 0,16

23-01-2011 08:33 17:10 0,20 0,47 0,19

30-01-2011 08:24 17:23 0,28 0,70 0,28

06-02-2011 08:12 17:35 0,37 0,84 0,33

13-02-2011 08:00 17:38 0,44 0,90 0,36

20-02-2011 07:46 17:39 0,54 1,01 0,40

27-02-2011 07:31 17:39 0,59 1,00 0,40

06-03-2011 07:15 17:40 0,64 0,99 0,39

13-03-2011 07:00 17:40 0,71 1,05 0,41

20-03-2011 06:43 17:39 0,87 1,19 0,47

27-03-2011 07:27 18:39 0,93 1,18 0,47

03-04-2011 07:11 18:39 1,14 1,35 0,53

10-04-2011 06:55 18:39 1,38 1,59 0,63

17-04-2011 06:39 18:39 1,48 1,62 0,64

24-04-2011 06:25 18:39 1,58 1,68 0,66

01-05-2011 06:12 18:39 1,65 1,64 0,65

08-05-2011 06:09 18:40 1,75 1,68 0,66

15-05-2011 06:07 18:41 1,94 1,83 0,72

22-05-2011 06:07 18:43 2,06 1,88 0,74

29-05-2011 06:06 18:45 2,06 1,81 0,71

05-06-2011 06:07 18:46 2,33 2,07 0,81

Date Sun-rise Sun-set Hor.Irr. Inc.Irr. Energy

-----------------------------------------------------------

12-06-2011 06:08 18:48 2,24 1,94 0,76

19-06-2011 06:09 18:50 2,26 1,96 0,77

26-06-2011 06:10 18:51 2,39 2,10 0,83

03-07-2011 06:12 18:52 2,27 2,00 0,78

10-07-2011 06:14 18:53 2,19 1,93 0,76

17-07-2011 06:15 18:53 2,06 1,85 0,73

24-07-2011 06:17 18:52 1,95 1,80 0,70

31-07-2011 06:18 18:51 1,83 1,73 0,68

07-08-2011 06:18 18:49 1,73 1,67 0,65

14-08-2011 06:21 18:46 1,63 1,63 0,64

21-08-2011 06:33 18:43 1,57 1,65 0,64

28-08-2011 06:44 18:40 1,46 1,58 0,62

04-09-2011 06:55 18:36 1,39 1,63 0,63

11-09-2011 07:07 18:32 1,13 1,33 0,52

18-09-2011 07:18 18:27 0,93 1,15 0,45

25-09-2011 07:30 18:23 0,89 1,23 0,48

02-10-2011 07:42 18:19 0,77 1,15 0,45

09-10-2011 07:53 18:15 0,69 1,12 0,44

16-10-2011 08:05 18:12 0,61 1,09 0,42

23-10-2011 08:18 18:09 0,53 1,02 0,40

30-10-2011 07:30 17:07 0,44 0,94 0,37

06-11-2011 07:43 17:03 0,35 0,81 0,32

13-11-2011 07:56 16:51 0,26 0,60 0,23

20-11-2011 08:08 16:42 0,21 0,52 0,20

27-11-2011 08:19 16:35 0,18 0,43 0,17

04-12-2011 08:29 16:30 0,14 0,29 0,11

11-12-2011 08:38 16:27 0,12 0,25 0,10

18-12-2011 08:44 16:28 0,11 0,22 0,09

25-12-2011 08:48 16:31 0,11 0,21 0,08

-----------------------------------------------------------

Cum. irradiance on horizontal plane : 391,00 kWh/m² (1406,1 MJ/m²)

Cum. irradiance on (inclinated) panel : 443,00 kWh/m² (1593,2 MJ/m²)

Total expected energy by panels: 174,00 kWh (625,4 MJ)

NOTES: Irradiation values in kWh/m².d , expected energy in kWh/d and all rising/setting times with

with respect to the (inclinated) solar panel surface

Example of TS data output file to examine your optimal installation and (yearly) capacity prognosis

14

APPLICATIONS

ASTRONOM : Astronomical (solar) dataTABUSOL : Computing solar panel energy productionFESA : Measure and compute your local horizon

R.C.Ott http://dutch.nl/rcott/astrohome.htm