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Abstract: This paper presents the results of the impact of a gravity-fed cooling technique applied to a photovoltaic module. The experiment shows that the technique increases the power output of the module by reversing the negative effects of elevated cell temperature on open circuit voltage, and this without the use of a circulating pump. The cooling technique employs the hydraulic head of water from an upstream source as the driving force that passes water over the back of the module, and this keeps the module temperature constant. The experimental results and the results of mathematical model on which it is predicated on are in very close agreement. [Copyright &y& Elsevier]

This paper evaluates one option to replace traditional cooking fuels in developing economies with a flexible, modular and clean solution of solar hydrogen, based on a numerical and experimentally tested system to address technical and safety issues. The study focuses on Ghana, Jamaica and Indonesia as examples of developing economies using fossil fuels for domestic cooking. Statistical analyses are performed and the domestic cooking demand profiles are created for these countries based on available data and a specific quantitative study in Ghana. The derived cooking demand profiles are used to size solar hydrogen plant case-studies for rural communities based on a TRNSYS numerical model. The results indicate that hydrogen plant sizing and management satisfy annual cooking demands of the communities which are 621.6 kg H 2 for Jamaica, 631 kg H 2 for Indonesia and 785 kg H 2 for Ghana. The effect of the weather data on the simulation is estimated by comparison between TMY and recent weather data for Jamaica. Finkelstein-Schafer statistics indicate differences between the composite and recent weather data, but these prove to have minor effect on simulation results, with 0.9% difference in hydrogen generation. The potential to establish solar hydrogen plants in the countries is further evaluated by creating novel solar hydrogen potential maps. [ABSTRACT FROM AUTHOR]

This paper describes the development of a semi-empirical numerical model for a solar hydrogen system consisting of a proton exchange membrane electrolyser (PEM) powered by photovoltaic panels to produce hydrogen as fuel for cooking applications, focussing on Jamaica as a suitable case-study. The model was developed in TRNSYS and includes a novel numerical component based on FORTRAN to model the operation of the PEM electrolyser. The numerical component was developed based on operational data from a purpose constructed small-scale experimental rig. The numerical model was calibrated using data from the experimental rig powered by operational data from a photovoltaic panel system in the UK and predicted photovoltaic panel power data from Jamaica. For the test conditions, experiments indicated an electrolysis maximum efficiency of 63.6%. The calibrated model was used to develop a case study analysis for a small community in Jamaica with a daily cooking demand of 39.6 kWh or 1.7 kg of H 2 gas. Simulations indicate that the H 2 production plan is sufficient for the cooking needs of the case-study. [ABSTRACT FROM AUTHOR]