The Development of the I-V Measurement by Pulsed Multi-Flash, and the Effectiveness
In order for the device to measure the I-V characteristics of the photovoltaic (PV) module to be used in the PV module assembly line, easy handling of the module, improvement of measurement accuracy, and reduction of the measuring time are strongly requested. We developed the solar simulator with several milliseconds flat pulsed light of multi flashes and accomplished the improvement of measurement accuracy, and the reduction of the measuring time. Both I-V measuring device and measuring method we developed are also effective in estimating the characteristics of response, light induced change, and being newly developed PV modules
Measurement system for fast power and energy rating of photovoltaic devices
This thesis presents a new type of solar simulator and new measurement
methods that allow for fast power rating of photovoltaic devices and for fast
performance measurements for energy rating and energy yield predictions
indoors under controlled, and more realistically simulated outdoor conditions.
A novel indoor measurement system for photovoltaic device characterisation
based on light emitting diodes (LEDs) as the light sources is described. The
solar simulator is capable of reproducing spectral changes seen in natural
sunlight, with its intricacies of variable air mass and weather conditions, to a
better match than previously possible. Furthermore, it allows measurements
under varying light intensity and device temperature.
The prototype LED-based solar simulator developed is characterised and its
measurement quality is analysed. The system achieves a class BAA solar
simulator classification with a class B spectral match, class A light intensity
uniformity and a class A temporal stability. It is the first system of its kind that
meets the standards of a solar simulator in spectral match to the standard
sunlight spectrum and in terms of minimum light intensity. An uncertainty
analysis shows that calibration uncertainty for crystalline silicon solar cells is
5% in maximum power with a 95.45% level of confidence. Recommendations
for further versions of the solar simulator are given and show potential of
reducing this uncertainty down to 2.9% across all measurement spectra
(1.8% with a primary calibrated reference cell).
A new method for automated power-rating of single- and multi-junction
devices is developed. The method uses a unique spectral response
measurement and fitting method. It eliminates the need of external
measurement equipment for determining spectral response. A simulated
characterisation of an amorphous silicon single- and double-junction solar
cell show accuracy of better than 0.5% in maximum power. First
measurements on the LED-based solar simulator show a measurement error of 4.5% in maximum power, which is due to a lack of measurement feedback
of spectral output and measurement irradiance.
The first three-dimensional performance matrix for use in photovoltaic energy
rating is reported, utilising the LED-based solar simulator. Device
characteristics are measured indoors under varying irradiance, temperature
and spectrum. A measurement method is detailed and utilised on a
crystalline and amorphous silicon solar cell. It allows for the first time a direct
investigation of spectral effects on photovoltaic devices under controlled
conditions. Results show that amorphous silicon devices are very sensitive to
changes in spectrum. Thus, spectral effects should not be neglected in energy yield predictions for such devices.
Biodiversity, conservation, and sustainable development
This important book highlights the conflicts between economic growth and the conservation of nature in the context of sustainable development. It places particular emphasis on biological diversity and examines possible policies for resolving conflicts which arise from the contrasting goals of conserving the natural environment and economic growth.