India has a lot of remote villages/settlements in hilly regions that cannot be connected to the power grid in the near future. Either the villages are so small (and hence powering them up might be economically unfeasible) or the power transmission infrastructure/cables cannot be taken through the mountains/thick jungles.
In many of these places renewable energy technologies is our only option. We can use solar panels or micro wind mills to generate electricity. But for places that have naturally flowing water streams/rivers, we can also look at installing micro hydro power plants to generate energy.
Consider this: Most of the villages/settlements are already located near a river because the river provides water for their living/agriculture needs. Most of these streams/rivers/water-falls are perennial. These water bodies have a lot of potential energy (stored in the water accumulated up-stream), which is released as Kinetic energy of the flowing water. This kinetic energy can be harnessed to generate electric power.
Competitively priced micro hydro power plants are available in smaller capacities that can be used to power small 30-member villages (for example). A small 10 kW turbine/3-phase 750 RPM generator can power lights, fans, radio, etc. inside houses and lights in few public places in such a village, for many hours in a day.
The basic idea behind micro hydro generators is to use the running water to turn the turbine blades which in-turn rotates the generator to generate power. Since the source of electricity generation is near the villages, power transmission losses can be avoided to a great degree. The Indian Government even provides subsidies to selected micro hydro power plant projects.
Major components of a Micro Hydro Power Plant
It is preferable to construct micro hydro power plants on a separate man-made channel that runs parallel to the river. Some water from the upper stream of the river can be diverted through this channel and after passing through the power plants, the water is re-introduced into the river/stream. Arrangements can be made so as to stop fishes,aquatic species, dirt, etc. from getting into this channel. It is also preferred to de-silt the water in order to prevent any corrosion to the turbine blades on the long run.
Forebay Tank: The Forebay tank stores a small quantity of water (near its entry point in the upperstream) to provide water on-demand to start the generator units, etc.
Penstock: Penstock is a long tube that can be constructed using steel/RCC that directs water from the Forebay tank into the power-plant/turbine. It may be partially buried into the earth. A gate valve can be installed at the water-flow entry point in order to control the flow of water.
Spillway and spillway channel: The spillway/spillway channel diverts the water from the Forebay tank back into the stream/river during power plant shutdown/maintenance.
Power House: The power house is a closed structure (probably made of bricks or stone) that will house the turbine, power generator, electrical protection devices, power measuring devices and other instruments required for regular maintenance.
Tail Race Channel: Tail race channel will direct the water from the power plant back into the stream/river. Due to this, micro hydro power plants do not 'consume' any water required for agriculture, etc. in the lower regions and does not affect the environment/aquatic species present in the river.
Micro hydro power plants are like mini dams, but they do not have the disadvantages of dams as they are designed only to generate electricity and not to store water.
We should aggressively look at installing such micro hydro power plants, especially in hilly regions/remote areas with access to a flowing stream (and without access to the electric grid). The maintenance charges of these power plants is very minimum. The power plant will stay in operation throughout the day (24 x 7) and hence batteries may not be required to store power (except a small battery to store power for emergency purposes).
The state of Arunachal Pradesh in India has set a good example in installing many such micro hydro power plants to electrify villages located in their hilly regions. Let us hope that other states will follow the example set by them.
The state of Arunachal Pradesh in India has set a good example in installing many such micro hydro power plants to electrify villages located in their hilly regions. Let us hope that other states will follow the example set by them.
