Satellite and camera-derived irradiance data for applications in low voltage grids with large PV shares

1. Deutsches Fernerkundungsdatenzentrum
Satellite- and (camera-derived) irradiance data for
applications in low voltage grids with large PV shares
Marion Schroedter-Homscheidt, Gerhard Gesell, Lars Klüser, Miriam Kosmale, Sandra
Jung, Niels Killius
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Earth Observation Center (EOC)
Holger Ruf, Gerd Heilscher
Hochschule Ulm
Contributions fromV.H. Peuch and
A. Benedetti (ECMWF),
L.Wald and M. Lefèvre (Armines),
E.Wey (Transvalor)

2. Deutsches Fernerkundungsdatenzentrum
Introduction
• Satellite-based solar resource information – New Copernicus/MACC service
• What‘s that? What is new?
• What else do we with the intermediate Copernicus service results?
• Cloud/snow statistics
• Dust aerosol statistics
• Nowcasting clouds for large solar power plants -> low voltage grids?
• Feed-in power and transformer load flow in a low voltage grid
• Cloud cameras – can we use NWP instead of a ceilometer for
cloud height assessment?

3. Deutsches Fernerkundungsdatenzentrum
Introduction
• Satellite-based solar resource information – New Copernicus/MACC service
• What‘s that? What is new?
• What else do we with the intermediate Copernicus service results?
• Cloud/snow statistics
• Dust aerosol statistics
• Nowcasting clouds for large solar power plants
• Feed-in power and transformer load flow in a low voltage grid
• Cloud cameras – can we use NWP instead of a ceilometer for
cloud height assessment?

4. Deutsches Fernerkundungsdatenzentrum
MACC-III -The Copernicus Atmosphere Service‘s precursor
Air quality
Global
Pollution
Aerosol UV
http://atmosphere.
copernicus.eu

5. Deutsches Fernerkundungsdatenzentrum
Physical retrieval method Heliosat-4
Scattering through
clouds and
aerosols
diffuse
irradiance
direct and diffuse
irradiance
Global irradiance
Absorption from
clouds,
aerosols, and
water vapour
diffuse
irradiance
Direct
normal
irradiance
Fast radiative transfer model = Heliosat-4

6. Deutsches Fernerkundungsdatenzentrum
McClear clear sky irradiance (GHI, DIF, DIR, DNI)
time series in 1 min steps and in global coverage
• 2004-2015 1-2 days delay online
• 7 years operations secured,
> 20 years planned
• Just register and
download from
http://www.soda-pro.com/ web-
services/radiation/
mcclear
• Interactive and OGC script
access possible

7. Deutsches Fernerkundungsdatenzentrum
MACC-RAD: Heliosat-4 irradiance
(GHI, DIF, DIR, DNI) time series in 15 min steps in
Europe/Africa/Middle East
• 2004-2015 1-2 days delay online
• 7 years operations secured,
> 20 years planned
• Just register and
download from
http://www.soda-pro.com /web-
services/radiation/
macc-rad
• Interactive and OGC script
access possible

8. Deutsches Fernerkundungsdatenzentrum
 Registration needed to justify existence of service
 Free for any use – commercial as well as R&D
 Only restriction: Do not sell the data itself without modifications
Data policy
Here you can find Data Policy and
User‘s Guide

9. Deutsches Fernerkundungsdatenzentrum
Olympic goals in solar resources:
Aim to be more accurate, better resolved, more parameters…
But is that all?
Today’s situation: ‘I’m asking 5 data providers and will get 6 different answers …
and now there is also MACC/Copernicus’
Sure, better, more accurate, more parameters is needed…
But also:
 transparency – which input data is used?
Publish instead of company confidential status
 Detailed validation – publish instead of treated as company confidential
 Continuous validation and quality control with experienced staff – no
project like approach with new PostDoc students every few years
Faster, higher, wider,…. Is that all?
Or: Why a new Copernicus service?

10. Deutsches Fernerkundungsdatenzentrum
What can we do with Copernicus/MACC intermediate data?

11. Deutsches Fernerkundungsdatenzentrum
Cloud and snow statistics
Carpentras, France
green = clear
blue = overcast/broken clouds
yellow = cirrus, thin ice
red = scattered clouds

12. Deutsches Fernerkundungsdatenzentrum
Cloud and snow statistics
green = clear
blue = overcast/broken clouds
yellow = cirrus, thin ice
red = scattered clouds
La Réunion
Carpentras, France

13. Deutsches Fernerkundungsdatenzentrum
Dust aerosol statistics – extinction, dust events from MATCH
GHI, IEED_5 GHI, IEED_10
number of exceedance days per year
IEED = Irradiance Extinction Exceedance Day
Thresholds 5, 10, 30% for GHI
10,30,50,70% for direct irradiances
Based on a 30 years climatology of daily
dust aerosol optical depth

14. Deutsches Fernerkundungsdatenzentrum
Duration of dust events – as seen in MATCH
maximum number of consecutive IEED days
GHI, IEED for 10% extinction
mean number of consecutive IEED days
GHI, IEED for 10% extinction

15. Deutsches Fernerkundungsdatenzentrum
Nowcasting for solar power plants
©
EUMETSAT/DLR
sequence of cloud masks
thin ice clouds
water/mixed phase clouds
cloud mask
forecast
irradiance forecast (Heliosat-4)
©
EUMETSAT/DLR
©
EUMETSAT/DLR
production forecast
marketoperations
© Eumetsat/DLR

16. Deutsches Fernerkundungsdatenzentrum
Feed-in power and transformer load – Ulm example
Grid simulation
Solar irradiance
at the surface
monitoring
forecast
Optimized solar energy integration
into the existing grid – grid status (historical data)
and nowcasting (expected to be used)
NWP
-17
-6
-45
-3/1
-11
-8
-5
-5
-69
-25
-26
-18-24
-11
-2
-4
-58
-3
-67

17. Deutsches Fernerkundungsdatenzentrum
Pyranometers
 more accurate at the point
 few locations only
 maintenance needed
Satellite
 spatially averaged
 15 or 5 minutes
 Long history available
Satellite or ground observations ?

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Test site Ulm Einsingen
• 12 PV-Systems with smart meters (red marked)
• 15 minute resolution
• 6.7.2013 – 13.12.2014
• Comparison of individual systems and sum

19. Deutsches Fernerkundungsdatenzentrum
Feed-in power – Comparison vs smart meters
Pyranometer (HSU)
MACC-RAD

20. Deutsches Fernerkundungsdatenzentrum
From feed-in power to load flow
at the transformer

21. Deutsches Fernerkundungsdatenzentrum
Load flow at transformer
Only values with sun elevation angles >0° are considered
Annual results for 2012

22. Deutsches Fernerkundungsdatenzentrum
Sky cameras and cloud height – can we save money for a ground based ceilometer
network and use the numerical weather prediction instead ?
Besides the question if sky cameras with their 10 minute forecast horizon and
restricted field of view are of interest at all for low voltage systems… , but PV and CSP
power plants might be interested…
A bit on cameras…

23. Deutsches Fernerkundungsdatenzentrum
Cameras and cloud height
Cloud detection
Cloud position
Cloud motion
Nowcast
y
x
z

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Remember – ceilometers are not cheap and they are point obs

25. Deutsches Fernerkundungsdatenzentrum
A real case in a ceilometer at PSA, Almeria, Spain
within 5
minutes
grey =
P25 and P75
within 5 min
MODIS image
at 13:10 UTC

26. Deutsches Fernerkundungsdatenzentrum
Can I use numerical weather prediction‘s cloud condensation
levels as from ECMWF?
multilayer
situation
All cases scattered
Rmsd 5.5 km 5.5 km
Bias 1.09 km 1.17 km
Pearson
corr.
0.50 0.43
only scattered
all

27. Deutsches Fernerkundungsdatenzentrum
 The new MACC/Copernicus irradiance service has been presented
 Usage of cloud properties from space for extended site characteristics
 Usage of aerosol properties from long-term modeling for site characteristics
 Cloud properties used in nowcasting for large scale solar power plants
 MACC irradiances for feed-in power calculation and transformer loads
in low voltage grids
 Quantification of ECMWF cloud base height vs ceilometer in Spain
Wrap-Up

28. Deutsches Fernerkundungsdatenzentrum
This work has recently received funding from the European
Union’s Seventh Programme for research, technological
development and demonstration under grant agreement No
608623 and 608930.
Thanks to …
… Stadtwerke Ulm for providing smart meter and transformer data
… the MACC team for providing data
… ECMWF for providing forecast data
… EUMETSAT for providing MSG satellite observations