Atul K. Raturi

Techno-economic analysis of a hybrid mini-grid system for Fiji islands

The Pacific Island Countries constantly struggle with the challenges of high petroleum dependence for their electricity production and lack of adequate energy services. It is possible to alleviate the energy poverty by utilizing abundant renewable energy resources available in the region. The objective of this work is to investigate the feasibility of a wind/solar photovoltaic/diesel generator-based hybrid power system in a remote location in Fiji islands. We used the Hybrid Optimisation Model for Electric Renewables (HOMER) software to simulate the system and perform system optimisation analysis. The system characteristics were studied in terms of optimal configuration, net present cost and the cost of energy. An entirely renewable energy-based configuration is feasible if 10% annual capacity shortage is allowed, while for a scenario with no capacity shortage, addition of a diesel generator is necessary. The addition of renewable energy components results in greenhouse gas reduction which could be used for carbon trading.

Investigation of some common Fijian flower dyes as photosensi-tizers for dye sensitized solar cellsabstract

Dye sensitized solar cells (DSSC) were fabricated using Allamanda cathartic, Bougainvillea spectabilis and Cosmos sulphureus dyes obtained from local Fijian flowers. The photoanodes were made from electro-phoretiaclly grown Titanium dioxide films coated with dyes. DSSCs with Cosmos sulphureus exhibited the best efficiency of 0.54% followed by Allamanda cathartic (0.40%) and Bougainvillea spectabilis (0.38%). The photoaction spectra of these cells were also studied.

Optimization and sensitivity analysis of a PV/Wind/Diesel hybrid system for a rural community in the pacific

This work looks at the feasibility of a standalone hybrid power generation system for providing power to a rural community in the Pacific Islands. The optimization and sensitivity analysis of a proposed PV/Wind/Diesel hybrid System is performed together with economic analysis. We have used HOMER, a sizing and optimization tool for distributed power system, developed by National Renewable Energy Laboratory (NREL) for our analysis. The sensitivity analysis was done using wind speed data and diesel price as variables. An Ice storage facility having a corrected mean daily load of 60 kWh/day was considered as the stand-alone load. The life cycle cost analysis was done for a number of scenarios with different renewable energy contribution to the total electricity produced.

Feasibility study of a grid connected photovoltaic system for the central region of Fiji

The paper also outlines the many aspects of grid connected solar power system that makes it viable and economically attractive.

Feasibility study of a solar water pumping system

Solar photovoltaic (SPV) water pumping systems have the potential to provide clean drinking water to millions of unserved people around the world. The abundant solar energy resource and groundwater availability in the Pacific Island Countries (PICs) can be combined to make much needed potable water available to remote island communities in these countries. This paper looks at the feasibility of using a SPV pumping system in one of the villages in the Fiji Islands.

Deposition and characterisation of titanium dioxide films formed by electrophoretic deposition

Nanocrystalline titanium dioxide (TiO2) films were deposited on glass substrates by electrophoretic deposition (EPD). Films were grown using the constant current and constant voltage methods and key EPD parameters were investigated. Anatase TiO2 powder, dissolved in deionised water with iodine and acetylacetone as dispersing agents was the colloidal suspension utilised. TiO2 particle concentration of 1 gl–1 and films annealed at 100°C exhibited the best properties. As the applied voltage and current densities increased, the film thickness increased. Thickness of the TiO2 films increased linearly during the initial period of EPD but the deposition rate subsequently decreased and attained a constant value for longer durations. At higher applied voltages and current densities, as-grown films were discontinuous with cracks. Optical measurements were used to determine the band gaps of deposited material. These films have potential for being used in dye sensitised solar cells.

Optimization of a Stand-Alone Renewable Energy System for a Small Load Requirement

Optimization of a stand-alone Renewable Energy (RE) system involves selecting the best RE resources and components, and sizing the system accordingly to get the most efficient and cost-effective solution. Design and optimization of an RE power system to serve the lighting in a University of the South Pacific car park was carried out using HOMER software and compared to manual calculations. Resource analysis showed that on average the site received 3.8 kWh m−2 day−1 of solar energy, with 1,387 full sun hours annually. Monthly average wind speed of 3.88 m s−1 at 10 m above ground level extrapolated to 15 m (the hub height of the wind turbine) resulted in an average wind speed of 4 m s−1, with power density of 70 Wm−2. With this wind resource, a Whisper 100 wind turbine would be in operation for approximately 50 % of the time in the year. The complementary nature of solar and wind resources showed good potential for a solar-wind hybrid system. In this study three possible systems—a PV system, a wind power system, and a hybrid power system (PV-wind)—were analyzed. It was found that a hybrid system is the best and most cost-effective option, as it is able to provide reliable power whilst minimizing the need for battery storage compared to a single RE power system. The optimum system comprised 0.270 kWp PV combined with a 900 W Whisper wind turbine with total battery storage capacity of 440 Ah at 12 V. Manual calculations yielded results similar to the HOMER simulations.