Micro-hydro generation

Micro-hydro systems use the natural flow of water to yield up to 100 kW output of electrical energy [22]. Simplicity, efficiency, longevity, reliability, and low maintenance costs make these systems attractive for mral development [23]. Like solar and wind, the fuel source for microhydro power is free, and the use of hydro-powered turbines to generate electricity produces no on-site air pollution. 

Hydro-electricity is the most developed renewable resource worldwide, even if it has to face social and environmental barriers [29]. In fact societal preferences are difficult to predict, while hydro-sites are often difficult to reach, which results in high transmission and capital investment costs. These are difficult to be accepted by private power companies. The global economic hydropower potential ranges between 7000 and 9000 TWh per year. Particularly mral communities without electricity appear to be convenient for small (<10 MWe), mini- (<1 MWe), and micro- (<100 kWe) scale hydro schemes. They have low environmental impacts, and generation costs are around 6-12 c/kWh. Emissions of GHG linked with hydro-electricity operation are due to flooding of land upstream of a dam that can imply a loss of biological carbon stocks and can produce methane emissions due to vegetation decomposition. 

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