Wednesday, October 29, 2008

Micro-hydro: Power for new Generation

Navtej Kohli assuming that the era will come after few year when the people able to made small amount of power for its own use . Solar energy is the best means which make everybody to generate electricity for small use. Everybody knows about hydroelectricity power. But it seems very costly a person to generate power using water . But MicroHydro make it possible to generate energy for small use. Also the costing, maintenance also very low for making a MicroHydro plant .

Basically the term Microhydro related to the installation of hydroelectric power which can able to produce upto 100KW. The condition which is required for this plant is water rich area such as Remote Area Power Supply (RAPS). Some countries like Solomon Islands also generating and supplying small amount of power like 50kw with Microhydro.
It can be made with pelton wheel for high head and low flow water supply, for this installation just like small dammed pool just in the top of the waterfall which have several hundred feet of pipe leading to a small generator housing.
While making plan for installing low-headed MicroHydro plant its maintenance and mechanism are most important thing. Because low-headed system moves large amount of water and might be possible to be face encounter of surface debris. That’s why Banki turbine, a pressurized self-cleaning cross flow waterwheel, is often preferred for low-head microhydro power systems. Though less efficient, its simpler structure is less expensive than other low-head turbines of the same capacity. Since the water flows in, then out of it, it cleans itself and is less prone to jam with debris.
Most of the person considered Microhydro as complement photovoltaic solar energy systems because in many areas flow of the water rises in the winter season when the power of the sun are goes down.
Frequency stability
Many theories are behind what should be best frequency should be have for a ideal Microhydro system, but in the real scenario frequency of alternating current generated needs to match the local standard utility frequency. Usually controller valves the water supply to generate a constant frequency for motor and clocks. While taking normal controller under consideration, it is small programmable logic controller with custom program which use deadband to minimize valve motion such that valve wears out as slowly as possible, during water conservation.
A grid-linked system slaves its generator to the grid by measuring current, to assure that the power is always output, so the grid never drives the turbine. The usual scheme is to measure voltage across a shunt resistor on one of the phases. The external utility's grid controller provides precision frequency controls.
An independent system usually governs its long-term frequency from an external time standard. The hydropower's AC time may vary by several seconds per hour, but over many days, it doesn't vary at all. Traditionally a caretaker would compare a simple AC clock driven by the hydropower system to a shortwave clock broadcast and adjust the mechanical governor on the hydropower system until the AC clock read the same as the broadcast for a few minutes. Over time, the result would be good. With a modern PLC-based system, the caretaker can just set the PLC's clock periodically from a radio clock, say once per week. Some more-professional systems automatically set the controller's clock from a radio clock.



MicroHydro work Phenomenon

Rivers water are passed through settling basin to remove sediment which might be harmful for the turbine. After that water is make to flow into the Forebay Tank where it is directed downhill through a pipe called a penstock . After reaching at the bottom water drives specially made turbine to produce electricity.
Moreover Navtej Kohli appreciating MicroHydro system and want to make popular . Not only government but also private sector have to come up with new techniques for installing MicroHydro system which be low cost and low maintenance system.

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