Major system components of possible future energy supply based on hydrogen generated by utilising solar energy have been installed on an industrial scale at Neunburg vorm Wald, Germany. Consideration is given to the initial technical aspects of stepwise transition from present-day energy supply aligned primarily to fossil fuels. Focal points of the investigations being carried out under the project are performance of the plant subsystems (including PV arrays, electrolyzers, and fuel cell plants), most of which constitute prototypes of innovative technologies, and their interaction under practical operation conditions. Analysis of the work has yielded a reliable database for updated assessment of the prospects and challenges of solar hydrogen technology. The present review centres on the technology and operation of the facility with regard to the objectives and perspectives of the project.

The work described in this paper was carried out as part of the development of an advanced solar photovoltaic (PV) conversion system. During the design of the system, simulation of both the power chain and the control algorithms was found to be useful, but to simulate a system as a whole requires a non-application specific circuit-based simulation model of a PV array for a simulator such as Saber, or the well known SPICE. There were found to be no such models readily available and thus the development of one became necessary. This work successfully sought to develop a cheap, but effective system to characterize existing cells and generate the device-dependent data that provides the link between the environmental variables irradiance and temperature, and the electrical characteristics of the device.

The thin films used in the fabrication of solar panels can all be cut using lasers. Narrow tracks must be cut in order to section the films to create cells which are linked in series to generate a useful voltage from a single-sheet solar panel. Ideal tracks should be as narrow as possible to maximize the fill factor, yet still able to ensure a high electrical impedance across the cut. Each cut should not damage the underlying thin film. Track widths of the order of 15 μm have been cut in ITO (transparent tin oxide), amorphous silicon and aluminium, and various anti-reflection layers. For the cutting process, which is extremely fast and therefore highly cost effective, the optimum laser wavelength depends upon the film itself. Machines have been constructed which use 1.06 μm and 503 nm Nd:YAG wavelengths and 248 nm excimer laser wavelength. (1 page)