Comparison to conventional hydro.docVIP

Comparison to conventional hydro A low-head hydro project generally describes an installation with a fall of water less than 5 metres (16 ft). Most current hydroelectric projects require a large hydraulic head to power turbines to generate electricity. The hydraulic head either occurs naturally, such as a waterfall, or is created by constructing a dam in a river bed, creating a reservoir. Using a controlled release of water from the reservoir creates the head required to turn the turbines. The costs and environmental impacts of constructing a dam make traditional hydroelectric projects difficult to construct. Damless hydro capture the kinetic energy of rivers, channels, spillways, irrigation systems, tides and oceans without the use of dams Construction of a dam and reservoir has many environmental effects. For example, the damming of a river locks the movement both of fish upstream to spawn and of silt downstream to fertilize fields . In addition, he vegetation overwhelmed by the rising water decays to form methane a far worse greenhouse gas than carbon dioxide Since no dam is required, low-head hydro may dramatically reduce the following: The safety risks (of having a dam), avoiding the risk of a flash flood caused by a breached dam Environmental and ecological complications Need for fish ladders Silt accumulation in basin Regulatory issues The initial cost of dam engineering and construction Maintenance Removing silt accumulation. However, low-head units are necessarily much smaller in capacity that conventional large hydro tubines; many more must be built for a given annual energy production – some of the costs of small turbine/generator units is offset by lower civil construction cost. Just as for large hydro, not every site can be economically and ecologically developed; sites may be too far from customers to be worth installation of a transmission line, or may lie in areas particularly senstive for wildlife. Hydrokinetic turbines A “Hydrokinetic” turbine