Hans Georg Beyer

Modelling long-term module performance based on realistic reporting conditions with consideration to spectral effects

A model for the annual performance of different module technologies is presented that includes spectral effects. The model is based on the realistic reporting conditions but also allows for secondary spectral effects, as experienced by multi-junction devices. The model is validated against measurements taken at CREST and shows a good agreement for all devices. Combining this relatively simple model with ASPIRE, a spectral irradiance model based on standard meteorological measurements, allows the translation to other locations. The method is applied to measurements of different devices deployed in Loughborough University and the significance of certain effects is discussed.

Uncertainty Calculations in Pyranometer Measurements and Application

The uncertainty of pyranometer measurements should be traced back to the World Radiation Reference (WRR), a standard that is specified by the mean sensitivity of the World Standard Group (WSG). The WSG is build up by 7 primary standard pyrheliometers, operated at Davos, Switzerland. Analyzing the complete calibration chain for an individual field pyranometer, usually the uncertainty of its calibration constant is extracted as a unique figure depending on the calibration method. The common representation of the expanded uncertainty, specified by the manufacturer is global information on the accuracy of daily averages. For the use of pyranometers for e.g. test of solar energy components as solar collectors, this information on the global daily accuracy of the pyranometer is not sufficient. As the response of a solar collector to the irradiance shows nonlinearities, a more detailed analysis of the pyranometer uncertainties is necessary. This will be demonstrated for the analysis of the uncertainties of the test results — i.e. the collector coefficients and their uncertainties — and the resulting predictions of the energy gain by these devices. Ancillary information by the manufacturers will be used to discuss the uncertainty of individual measurements depending on e.g. ranges of those parameters that originate the uncertainties, depending on the geometry (incidence angle), ambient temperature and the sky conditions. Based on this information the inter-comparability of test performed at different times or with different instruments will be discussed.Copyright

Contributions to the knowledge base on PV performance: Evaluation of the operation of PV systems using different technologies installed in southern Norway

To assist in establishing an accepted knowledge base on PV-modules and systems performance using a representative range of technologies, devices have to be installed at diverse locations, covering a broad range of environmental conditions. For the example of a high latitude location, modules and systems are installed and under investigation in southern Norway (Kristiansand region) by the University of Agder in cooperation with industrial partners. This paper presents first results of the analysis of module performance. The operational behavior of the modules is used to derive a modeling scheme applicable for performance prediction. This use is demonstrated by giving the expected annual performance of different module technologies for a set of sites in southern Norway.

Towards Designing an Integrated Earth Observation System for the Provision of Solar Energy Resource and Assessment

The GEOSS strategic plan specifically targets the area of improved energy resource management due to the importance of these to the economic and social viability of every nation of the world. With the worlds increasing demand for energy resources, the need for new alternative energy resources grows. This paper overviews a new initiative within the International Energy Agency that addresses needs to better manage and develop solar energy resources worldwide. The goal is to provide the solar energy industry, the electricity sector, governments, and renewable energy organizations and institutions with the most suitable and accurate information of the solar radiation resources at the Earths surface in easily-accessible formats and understandable quality metrics. The scope of solar resource assessment information includes historic data sets and currently derived data products using satellite imagery and other means. Thus, this new task will address the needs of the solar energy sector while at the same time will serve as a model that satisfies GEOSS objectives and goals.

Performance of grid-connected PV system in Southern Norway

This paper presents performance results from one of the first grid-connected photovoltaic (PV) systems in Norway. The 45 kWp system is mounted on top of a flat roof at the headquarters of a local utility company, Agder Energi, in the coastal town of Kristiansand. The system consists mainly of multi-crystalline silicon modules, with one thin film array. The system has been in operation since May 2011 and is instrumented for research and monitoring purposes. Data recorded include global and diffuse horizontal irradiation, tilted irradiation and other weather parameters, PV module temperatures, DC and AC current and voltage for three arrays, in addition to inverter power data and voltage quality measurements. Similar performance data has not yet been published for Norway. The results so far indicate good conditions for solar utilization at this location with global horizontal irradiation around 1065 W/(m2yr) and around 50 % diffuse fraction. The system produces as expected from a design perspective, with specific yield reaching 950 kWh/kWp and PR approaching 0.8 in 2014. Improvement in PR is seen as operational experience increases and system downtime is reduced. PR loss can be attributed to part-shading of PV arrays from the surrounding building structures, snow coverage in winter and inverter outages.