---
_id: '24551'
abstract:
- lang: eng
  text: "Access to precise meteorological data is crucial to be able to plan and install
    renewable energy systems \r\nsuch as solar power plants and wind farms. In case
    of solar energy, knowledge of local irradiance and air temperature \r\nvalues
    is very important. For this, various methods can be used such as installing local
    weather stations or using \r\nmeteorological data from different organizations
    such as Meteonorm or official Deutscher Wetterdienst (DWD). An \r\nalternative
    is to use satellite reanalysis datasets provided by organizations like the National
    Aeronautics and Space \r\nAdministration (NASA) and European Centre for Medium-Range
    Weather Forecasts (ECMWF). In this paper the \r\n“Modern-Era Retrospective analysis
    for Research and Applications” dataset version 2 (MERRA-2) will be presented,
    \r\nand its performance will be evaluated by comparing it to locally measured
    datasets provided by Meteonorm and DWD. \r\nThe analysis shows very high correlation
    between MERRA-2 and local measurements (correlation coefficients of 0.99) \r\nfor
    monthly global irradiance and air temperature values. The results prove the suitability
    of MERRA-2 data for \r\napplications requiring long historical data. Moreover,
    availability of MERRA-2 for the whole world with an acceptable \r\nresolution
    makes it a very valuable dataset."
author:
- first_name: Arash
  full_name: Khatibi, Arash
  id: '43538'
  last_name: Khatibi
- first_name: Stefan
  full_name: Krauter, Stefan
  id: '28836'
  last_name: Krauter
  orcid: 0000-0002-3594-260X
citation:
  ama: 'Khatibi A, Krauter S. Comparison and Validation of Irradiance Data: Satellite
    Meteorological Dataset MERRA-2 vs. Meteonorm and German Weather Service (DWD).
    In: <i>Proceedings of the 38th European Photovoltaic Solar Energy Conference and
    Exhibition (EUPVSEC 2021)</i>. ; 2021:1141-1147. doi:<a href="https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11">10.4229/EUPVSEC20212021-5BV.4.11</a>'
  apa: 'Khatibi, A., &#38; Krauter, S. (2021). Comparison and Validation of Irradiance
    Data: Satellite Meteorological Dataset MERRA-2 vs. Meteonorm and German Weather
    Service (DWD). <i>Proceedings of the 38th European Photovoltaic Solar Energy Conference
    and Exhibition (EUPVSEC 2021)</i>, 1141–1147. <a href="https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11">https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11</a>'
  bibtex: '@inproceedings{Khatibi_Krauter_2021, title={Comparison and Validation of
    Irradiance Data: Satellite Meteorological Dataset MERRA-2 vs. Meteonorm and German
    Weather Service (DWD)}, DOI={<a href="https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11">10.4229/EUPVSEC20212021-5BV.4.11</a>},
    booktitle={Proceedings of the 38th European Photovoltaic Solar Energy Conference
    and Exhibition (EUPVSEC 2021)}, author={Khatibi, Arash and Krauter, Stefan}, year={2021},
    pages={1141–1147} }'
  chicago: 'Khatibi, Arash, and Stefan Krauter. “Comparison and Validation of Irradiance
    Data: Satellite Meteorological Dataset MERRA-2 vs. Meteonorm and German Weather
    Service (DWD).” In <i>Proceedings of the 38th European Photovoltaic Solar Energy
    Conference and Exhibition (EUPVSEC 2021)</i>, 1141–47, 2021. <a href="https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11">https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11</a>.'
  ieee: 'A. Khatibi and S. Krauter, “Comparison and Validation of Irradiance Data:
    Satellite Meteorological Dataset MERRA-2 vs. Meteonorm and German Weather Service
    (DWD),” in <i>Proceedings of the 38th European Photovoltaic Solar Energy Conference
    and Exhibition (EUPVSEC 2021)</i>, 2021, pp. 1141–1147, doi: <a href="https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11">10.4229/EUPVSEC20212021-5BV.4.11</a>.'
  mla: 'Khatibi, Arash, and Stefan Krauter. “Comparison and Validation of Irradiance
    Data: Satellite Meteorological Dataset MERRA-2 vs. Meteonorm and German Weather
    Service (DWD).” <i>Proceedings of the 38th European Photovoltaic Solar Energy
    Conference and Exhibition (EUPVSEC 2021)</i>, 2021, pp. 1141–47, doi:<a href="https://doi.org/10.4229/EUPVSEC20212021-5BV.4.11">10.4229/EUPVSEC20212021-5BV.4.11</a>.'
  short: 'A. Khatibi, S. Krauter, in: Proceedings of the 38th European Photovoltaic
    Solar Energy Conference and Exhibition (EUPVSEC 2021), 2021, pp. 1141–1147.'
conference:
  end_date: 2021-09-10
  name: 38th European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC
    2021)
  start_date: 2021-09-06
date_created: 2021-09-16T10:20:41Z
date_updated: 2022-01-06T13:29:51Z
ddc:
- '550'
department:
- _id: '53'
doi: 10.4229/EUPVSEC20212021-5BV.4.11
file:
- access_level: closed
  content_type: application/pdf
  creator: krauter
  date_created: 2022-01-06T13:26:47Z
  date_updated: 2022-01-06T13:26:47Z
  file_id: '29176'
  file_name: Khatibi Krauter - MERRA 2 vs Meteonorm - EUPVSEC 2021.pdf
  file_size: 2475972
  relation: main_file
  success: 1
file_date_updated: 2022-01-06T13:26:47Z
has_accepted_license: '1'
keyword:
- Energy potential estimation
- Photovoltaic
- Solar radiation
- Temperature measurement
- Satellite data
- Meteonorm
- MERRA-2
- DWD
language:
- iso: eng
page: 1141 - 1147
publication: Proceedings of the 38th European Photovoltaic Solar Energy Conference
  and Exhibition (EUPVSEC 2021)
publication_identifier:
  isbn:
  - 3-936338-78-7
publication_status: published
quality_controlled: '1'
status: public
title: 'Comparison and Validation of Irradiance Data: Satellite Meteorological Dataset
  MERRA-2 vs. Meteonorm and German Weather Service (DWD)'
type: conference
user_id: '28836'
year: '2021'
...
---
_id: '16899'
abstract:
- lang: eng
  text: To compare efficiency and yield of many micro-inverters available on the world
    market in 2014-2020, an in- and outdoor test laboratory at the University of Paderborn
    has been set up. The inverters have been fed by identical and calibrated crystalline
    silicon PV modules of 215 Wp. To monitor accurately DC input, AC power output
    and energy yield, each of the micro-inverters has been equipped with a calibrated
    electricity meter. For micro-inverters requiring control units for grid-feeding
    that has been acquired also. The comparison covers efficiency-load characteristics
    as well as electrical energy yields. Purchase costs vary considerably between
    the models in comparison, sometimes inverter costs are higher than module costs,
    particularly if an additional grid-connection or interface device is needed for
    operation. The weighted conversion efficiency according to EU and CEC standards
    has been measured and calculated. While some inverters have been optimized for
    high irradiance levels, they ranked better at the CEC efficiency, others performed
    very well also for low irradiance levels, thus ranking higher at in the EU-efficiency
    tables. These results are deviating from the actual energy yield measurements,
    which show a slightly different ranking. At one inverter, an accurate, but very
    slow MPPT algorithm that barely could follow quickly changing irradiance levels
    could be the reason for this effect. Another inverter switched off after operation
    at high power output for a while. Apparently, some inverters are been optimized
    to show excellent EU and CEC efficiency ratings. Two of the inverters featuring
    two inputs did not show an exceptional performance at the EU- and CEC-ratings,
    but they achieved top ranks at the AC energy yield for the first years. For the
    customer, the AC yield is a major performance indicator of any microinverter and
    should be included in the datasheet.
author:
- first_name: Stefan
  full_name: Krauter, Stefan
  id: '28836'
  last_name: Krauter
  orcid: 0000-0002-3594-260X
- first_name: Jörg
  full_name: Bendfeld, Jörg
  id: '16148'
  last_name: Bendfeld
citation:
  ama: 'Krauter S, Bendfeld J. Comparison of Microinverters: Update on Rankings of
    Conversion Efficiencies and Energy Yields. In: <i>Proceedings of the 47th IEEE
    Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL
    MEETING</i>. IEEE; 2020:1429-1432. doi:<a href="https://doi.org/10.1109/PVSC45281.2020.9300953">10.1109/PVSC45281.2020.9300953</a>'
  apa: 'Krauter, S., &#38; Bendfeld, J. (2020). Comparison of Microinverters: Update
    on Rankings of Conversion Efficiencies and Energy Yields. <i>Proceedings of the
    47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020
    VIRTUAL MEETING</i>, 1429–1432. <a href="https://doi.org/10.1109/PVSC45281.2020.9300953">https://doi.org/10.1109/PVSC45281.2020.9300953</a>'
  bibtex: '@inproceedings{Krauter_Bendfeld_2020, place={online}, title={Comparison
    of Microinverters: Update on Rankings of Conversion Efficiencies and Energy Yields},
    DOI={<a href="https://doi.org/10.1109/PVSC45281.2020.9300953">10.1109/PVSC45281.2020.9300953</a>},
    booktitle={Proceedings of the 47th IEEE Photovoltaic Specialists Conference (PVSC
    47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING}, publisher={IEEE}, author={Krauter,
    Stefan and Bendfeld, Jörg}, year={2020}, pages={1429–1432} }'
  chicago: 'Krauter, Stefan, and Jörg Bendfeld. “Comparison of Microinverters: Update
    on Rankings of Conversion Efficiencies and Energy Yields.” In <i>Proceedings of
    the 47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21,
    2020 VIRTUAL MEETING</i>, 1429–32. online: IEEE, 2020. <a href="https://doi.org/10.1109/PVSC45281.2020.9300953">https://doi.org/10.1109/PVSC45281.2020.9300953</a>.'
  ieee: 'S. Krauter and J. Bendfeld, “Comparison of Microinverters: Update on Rankings
    of Conversion Efficiencies and Energy Yields,” in <i>Proceedings of the 47th IEEE
    Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL
    MEETING</i>, VIRTUAL MEETING, 2020, pp. 1429–1432, doi: <a href="https://doi.org/10.1109/PVSC45281.2020.9300953">10.1109/PVSC45281.2020.9300953</a>.'
  mla: 'Krauter, Stefan, and Jörg Bendfeld. “Comparison of Microinverters: Update
    on Rankings of Conversion Efficiencies and Energy Yields.” <i>Proceedings of the
    47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020
    VIRTUAL MEETING</i>, IEEE, 2020, pp. 1429–32, doi:<a href="https://doi.org/10.1109/PVSC45281.2020.9300953">10.1109/PVSC45281.2020.9300953</a>.'
  short: 'S. Krauter, J. Bendfeld, in: Proceedings of the 47th IEEE Photovoltaic Specialists
    Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING, IEEE, online,
    2020, pp. 1429–1432.'
conference:
  end_date: 2020-08-21
  location: VIRTUAL MEETING
  name: 47th IEEE Photovoltaic Specialists Conference (PVSC 47)
  start_date: 2020-06-15
date_created: 2020-04-29T05:31:12Z
date_updated: 2022-01-07T10:10:43Z
department:
- _id: '53'
doi: 10.1109/PVSC45281.2020.9300953
keyword:
- yield
- AC
- micro-inverter
- MPPT
- CEC rating
- EU efficiency
- Photovoltaic
- Solar
language:
- iso: eng
main_file_link:
- url: https://ieeexplore.ieee.org/document/9300953
page: 1429-1432
place: online
publication: Proceedings of the 47th IEEE Photovoltaic Specialists Conference (PVSC
  47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING
publication_identifier:
  issn:
  - ' 0160-8371'
publication_status: published
publisher: IEEE
quality_controlled: '1'
status: public
title: 'Comparison of Microinverters: Update on Rankings of Conversion Efficiencies
  and Energy Yields'
type: conference
user_id: '28836'
year: '2020'
...