In some areas, diesel-powered electric generators, oil-burning lamps, batteries, and other substitutes can meet some of the energy demands. More remote communities have no electricity at all. .
When determining the best way to address the electricity needs of the developing world, attention should be given to renewable energies. Renewable energies are natural, non-depleting sources of power, and this paper focuses on only .
three of the various types: solar, wind, and hydropower. "Renewable energy technologies have made substantial advancements in efficiency and price reduction, and in many cases they are cost-effective alternatives to fossil fuel-based power plants" (Harrison and Whittington, 2001, pp. 78-79). Renewable energies are also important because they have unique environmental advantages over conventional energy sources. .
Renewable Energy Technologies .
Solar energy can be harnessed in a number of different ways-by capturing solar radiation, with concentrated solar power, with passive solar heating, and with photovoltaic cells. Because of the complexity of each of these technologies, the most common one used to generate electricity is the photovoltaic cells (also called PV cells or solar cells). The PV cells convert sunlight into electricity and of course there are some advantages and disadvantages of this technology. Wind energy is perhaps the oldest form of natural power harnessed by humans, used 7,000 years ago to propel boats down the Nile. Most people probably associate wind energy with either windmills used for pumping water or with modern wind turbines used to produce electricity (Danish Wind Energy Association, 2002). .
Hydropower is the most commonly utilized renewable resource. Energy can be harnessed from river flow, tidal changes, wave motion, and in the thermal ocean currents. Among these technologies the most popular one is based on river flow-large-scale hydroelectric dams, micro-hydro facilities, run-of-river projects, and diversion hydropower.
