Tuesday, August 30, 2011

Micro-hydro electricity

I mentioned in our August letter that I recently visited several hydroelectric power projects.  These projects are not part of our community development project, but a renewable energy project also run by our organization.  Engineers in our organization have put more than a decade into refining the technology that is now spreading around the country.  They used to run a production workshop in the capital city, doing R&D on various turbines, and then training local steelsmiths to produce them.  When they settled on a standard technology, it started to spread to private workshops, and then the project no longer needed to run a production workshop.  Now the effort of the project is installing micro-hydro plants in remote underserved villages. 

The first thing to be said about hydroelectricity in this country is that foreigners did not bring this idea here.  For many many years the local people here have been harnessing the power of moving water.  The first way they used the force of moving water was to grind their wheat into flour.   

This is a locally made flour mill.  A chute of water drives a horizontal paddle-wheel of sorts, turning the vertical shaft that this grinding wheel sits on.  It looks like a slow process, but the energy is free, and that's worth a lot!

I have not yet found a source that could tell me when the first hydro-electric experiments were done by locals.  Today's locally made hydro-power plants look like this.  The same sort of horizontal paddle-wheel is driving the big pulley from below, and the big pulley drives the electric generator.

Some of these locally-made powerplants have 6-7 meters of head (distance of water fall before it reaches the paddle-wheel), and that's enough to make quite a water spray!  This system might generate around 5 kilo-watts.  A more efficient turbine could double the output from this much head.

Here's another view of the foaming water rushing out of this locally made micro-hydro plant.  From the spot I was standing to take this picture there was a misty cool breeze that felt amazing in the 105 degree heat!

Here's another village that has constructed their grain mill and local micro-hydro side-by-side.  They only  run one at a time: grain mill in the day, and electricity at night.  With a more efficient turbine they would be able to run both at the same time.

This was one of the first locally made micro-hydro plants I saw in the Lal area in 2008.  this huge handmade pulley  was very rickety, and a lot of efficiency was lost on the lack of proper bearings.

The paddle-wheel being driven by water was also quite rickety.  The fall here had an estimated potential of producing 5 KW, but this design was gathering less than 1 KW.  While it's great for communities to use all local materials and knowledge, but it's also a huge disappointment for them that their work doesn't produce the results it should.

Here's the turbine that our org's renewable energy project developed.  Water enters from a 16 or 20 inch fallpipe.  The wheel pictured on top controls the water flowing in.  By fully enclosing the pipe and the turbine, no energy is lost, it's all driven through the hamster-wheel-like turbine.  This is a 10 KW plant, enough to light 300+ houses.

Along with the turbine, a power distribution box is enclosed in the powerhouse.  The project also supplies main lines that go out to all the clusters of houses, and smaller distribution boxes.  Each family can tap into the closest distribution box.

This is the water reservoir that feeds the 20-inch fallpipe.  It doubles as a great swimming hole.  (Don't worry, there's a steel grate to private boys from being sucked into the pipe!)

That's your brief picture tour of hydro-electric power at the village scale here.  A turbine and plant install like the last one pictured is not cheap (around $10,000), but it would cost much more to run grid powerlines to remote villages here.  In addition, these projects are not freebies, the villages that receive these micro-hyrdo plants must labor hard, without pay, as their form of participation for the project.  The villagers dig the foundations for the plant, build the water reservoir and powerhouse, lay the fall pipe, set up all the poles for the powerlines, and pull the lines.  During this process many villagers are learning how this technology works and how to put it together, and these laborers are then spreading the word of how well this technology works.  This helps to increase demand for the improved turbines to smaller markets, which will help this whole project replicate and be sustained by local engineers.  Well, that's the long range picture anyway!

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