Ajal Kumar

Wind characteristics and energy potentials at Wainiyaku Taveuni, Fiji

Purpose – The aim of this paper is to analyze the wind regime at Wainiyaku, Taveuni in Fiji, estimate Annual Energy Production (AEP) using a 275 kW Vergnet wind, and determine its economic viability.Design/methodology/approach – The only grid supply is in the northeast (suburban area) of the island. The main source is diesel generators, which are operated only certain hours per day. The study around Wainiyaku state was essential to determine an alternative continuous source of energy. The wind assessment on the island was based on the data provided by the Department of Energy (Fiji) and WAsP was used to reliably estimate the wind power potential on the island.Findings – The report suggested that Wainiyaku Taveuni is a good site for wind power generation based on mean wind speed at 30 m agl. The software predicted a resource grid for mean wind speed and power density around Wainiyaku. An economic analysis for a prospective wind power generation using Vergnet 275 kW showed a reasonable promise.Research limi...

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.

Identifying Energy Trends in Fiji Islands

This chapter intends to simulate the current situation of Fiji Electricity Authority’s transmission network of Viti Levu by using the load flow method and investigate the situation of the overall system. The first part of the chapter focuses on finding out the problems faced by Fiji Electricity Authority with the reliability of the network. After inspecting regions vulnerable to faults, different scenarios have been tested in steady state with different loads in various parts of Viti Levu. Reaction of the network was observed to determine the highest load level that the network can support before collapsing. The second part of chapter proposes recommendations to improve the reliability of the network. These recommendations are tested using the ETAP software in the form of scenarios by incorporating different possible choices with the current network, and the results obtained from each scenario are analyzed. This chapter concludes with the listing of recommendations that can be made in order to do further analysis for future expansion of the network through renewable energy sources (RES).

Producer Gas Fuelled Operation of a Solid Oxide Fuel Cell - Numerical Investigation

1 •Fuel cell is an electro-chemical device which converts chemical energy into electrical energy. 2 •Solid Oxide Fuel Cell is a type of fuel cell characterized by flexibility of the input fuel. 3 •Producer gas is gaseous bio fuel being used for power generation through the internal combustion engines route. 4 •Using producer gas in fuel cells is of interest considering the potential gain in conversion efficiencies.

Wind regime in the proximity of the 20 kW experimental turbine site at Nabua, Fiji

Renewable energy generated as much electric power worldwide in 2005 as one-fifth of the worlds nuclear power plants excluding large hydropower that itself accounts to 16% of world’s electricity (REN 21 2005). Renewable energy is gaining prominence in providing the world’s primary energy needs. Solar, wind, biomass, and geothermal are considered as the premier renewable energy resources that are in direct competition with the conventional fuels. The fastest growing technology has been the photovoltaic (grid connected), however, wind power is steadily growing with an estimated existing capacity of 56 GW by the end of 2005 (REN21 2005). Wind power has been used for many centuries to provide mechanical and electrical power for a variety of uses. Since the beginning of the last century, however, the most important use has been the generation of electricity for supply to rural and remote areas, as well as providing energy into the electrical distribution system, i.e. the national grid. World wind energy capacity has doubled every three years since 1990 and each doubling has been accompanied by a 15% reduction in the price of wind turbines (Milbrow 2005). Turbine size has increased from 600 - 800 kW to 1 - 3 MW with blade diameters from 60 -100 m and the energy costs (c/kWh) has declined by at least 18% and is now half those of 1990. The practical size of a wind turbine is determined by the assessment of annual electrical load, site conditions, wind resource, installed cost, and utility rate (Lodge 2005).The major countries that utilize wind power for electricity generation include the USA, Spain, Germany, India, Britain, Sweden, Netherlands, China, and Denmark. However, Russia, South Africa, Brazil, and Mexico are in the transitional stage to develop large-scale commercial markets. The basic theory of the extraction of energy from a wind turbine is found in any standard textbook on wind energy. The power in the wind varies as the cube of the wind speed. If an obstacle is placed in the path of the wind, the wind’s kinetic energy does work on the obstacle and wind energy is converted to other forms, including the kinetic energy of rotating parts. Thus a turbine or rotor placed in the path of wind, with wind speed,