Having moved to China about one
year ago, for the majority of the project design stage I have been working
remotely from the rest of the team, however given my convenient geographic
location to Nepal and imminent homeward bound journey to the UK we decided it
would be valuable for someone to visit the village and undertake some recognisance
and further site survey. Hence on the 12th December I stepped on a plane in
Shanghai bound for Kathmandu! My missions were to meet Oshin Power to discuss
their recent site survey (the Nepalese Hydro company that we hope will
fabricate our hydro turbine and support the project), find out more about the
exciting prospect of a new river with more power, get to know the
village/villagers and undertake some further site surveys. Anyhow after a heavy
fight delay I arrived in Kathmandu in time to meet Justin and Matthew from
learning planet for a quiet and very welcome beer to discuss the project a
little more.
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| A road from Balimtar |
The next morning in Kathmandu was
perhaps the only chilled part of the trip as in the afternoon Justin and I set
to planning the visit, the following day we were to meet Oshin Power in Butwal
(southern Nepal). This is almost a whole day by bus from Kathmandu which just
wasn’t going to fit the schedule so we had to hop on a dinky plane and jet over
the mountains – we arrived at Butwal airport which is a very small and rural
airport to say the least! The next morning I went to my first ever meeting by
rickshaw and we arrived at Oshin Power. The morning was spent discussing the
two options for Balimtar Pico Hydro project, option 1 being our original high
head low flow option. However during Oshin’s site survey the engineer had
cunningly spotted a much larger river with a low head and concluded by using
this alternative setup we could generate 2-3 kW instead of 0.75 kW with the two
river high head option. We were naturally over the moon with this prospect,
power delivery of this magnitude could be a real game changer for the village. After
the meeting we grabbed a bus up the nearby mountain (cars can’t access the road
as it is far too uneven), clambered across a huge cable rope foot bridge, and
hiked through a colourful mountain village to see a previous low-head high-flow
project that Oshin had constructed. Seeing the device up close was fantastic
and really hammers home that they are agricultural power stations utilising
nature to their best ability. The power house being perched on the edge of a
convenient drop in head with a handmade inflow channel snaking along the path
of an irrigation channel that had probably been there for 100s of years. This
project was only a 300 kW test bed and to crank up a scheme to 2-3 kW is going
to need a few more detailed studies on the drawing board, but after this trip
both Justin and I felt confident with Oshin Power’s help and our network of
pico-hydro experts we could make this happen in Balmitar!
Arriving back in Kathmandu there
was no time to waste as we had to prepare to travel to village the next day,
you might be thinking this means just quickly packing your rucksack…….well you
would be quite mistaken if that was the case………it involves packing up several
PV panels, huge rolls of carpet/underlay, pots of paint, dinner plates, empty
wine bottles and a whole host of provisions for the village! The next morning
somehow we got all this stuff and ourselves into one tiny taxi, we then
decanted this onto the roof of a minivan and started our travel to Guoka. This
is the main town near to Dhawa and Balimatar, here we collected more provisions
including a couple of huge lengths of concrete reinforcing bar for the new
school shower block. All this was then hoisted on top of the Dhawa bus, I say
bus it is more a cross between a bus and tractor. I was soon to find out why,
after six hours plus of exceedingly hair raising bendy and bumpy mountain tracks
we arrived in Dhawa. The views along the journey were just spectacular,
apparently only one year ago the bus didn’t exist to Dhawa and the route to the
village was up to 10 hours by foot! The reception in the village was amazing as
the bus arrived and all the children rushed with huge smiles to help carry all
the provisions off the bus, almost everything that the village needs beyond
what they grow arrives on the bus.
During our four day stay in the
village we would be staying with the wonderful hosts Giri Raj and his wife. Giri
is the school headmaster and key figure of the village and his family made us
so welcome. It’s fair to say the views from the Raj’s house are breath-taking,
a common feature of all homes in Dhawa. Other features are no running water, no
heating, open windows, dust floors, outside privy and VERY unreliable grid
electricity. However inside what people from home would call very simple living
accommodation is a buzzing and wonderfully happy family, certainly makes one
stop and think about all the unnecessary things we have back home. This warmth
and welcome spreads right across these two villages of Dhawa and Balimtar, a truly
special world. The next day we were up at sparrows f&%t and Justin took me
around to see the results of Learning Planet’s past and present projects. As I
stepped into the new school library and saw a group of 6 or more kids
surrounding a computer excitingly doing their homework and others scattered
around on the beanbags reading books, I suddenly realised what Learning Planet
means to these villages. I was then told the story of a mother and child
speaking to their husband/father for the first time in several years over
Skype, what a life changer the internet has been for this village. This is in a
very large part thanks to Mathew who I mentioned earlier, he is also working
with Learning Planet and Engineers Without Boarders. He is installing a wifi
mesh (called DhawaNet) across several mountain villages. Now let’s talk about
pico-hydro!
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| The river looking downstream from the water intake |
In the afternoon we marched down
to visit the new larger river, it certainly was delivering a large volume of
water and like the demonstration site we visited earlier with Oshin, it had an
almost perfect natural drop where we could fabricate the power house. I realised
that we had a pretty clear picture of the head drop of around 5 m but what
about the river flow? Unfortunately there is no quick/accurate flow measurement
method for larger rivers, such as diverting the entire river into a bucket. The
quickest technique is the “salt gulp” method with a conductivity meter, but
funnily enough the villages didn’t have one of those tucked away. The river bed
was too uneven and shallow to use a flow area and “floating orange” method, so
the only real solution was to fabricate a sharp crested rectangular weir and
divert the whole river through it. After a few quick and dirty calcs over a
Nepalise brandy I worked out the capacity of weir we needed and the next day we
set to and fabricated it from a section of plywood and lengths of aluminium
angle. With the weir ready to be installed we dashed off and surveyed the “old”
high head low flow scheme. Being high head this involved some extensive hiking
through dense undergrowth, we found the two small rivers with what looked like
a disappointing dribble after dealing with the larger river. If we reverted to
this option there would certainly be fun and games installing the penstock pipe
down the steep mountain side! Time was against us so this was just a quick
survey to get our bearings.
The final full day in the village
consisted of installing the weir in the morning, myself and two of the local
guys helping build Balimtar’s new primary school scuttled down the mountain to
the river armed with the weir, a number of stakes, a machete and sledge hammer.
We then waded into the freezing cold river water and started building, first we
had to dam half way across from both sides using large rocks and mud. Once this
was complete, it was a case of installing the pre-assembled weir and driving in
an upstream measurement stake. This stake is positioned 800 mm upstream of the
wear crest and by measuring the height of flow about it and utilising weir flow
theory the actual flow in the river can be established. Later we calculated the
flow at around 160 l/s. This would be expected to drop a certain amount as we
move further into the dry season but is a very positive starting point. We need
to know this variability so we can tune the system to the optimum head and flow
combination to maximise power.
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| The constructed weir looking upstream |
While all this was
going on, a group from a nearby village had requested we come and undertake a
quick site survey for them upstream. So while our friends finished shoring up
the dam and weir, Justin and I went upstream with the other villages. After an
extensive hike along the meandering river bank we spotted a suitable irrigation
channel and accompanying 4-5 m natural drop. We made a quick survey and thought
it could be possible to develop a further 1-2 kW scheme in the future….watch
this space! The final act of the day was taking some pictures of our new weir
and one last flow depth measurement before the sun went down. Then the final
hike of the trip up the mountain to Dhawa via Balimtar, whilst keeping a
watchful eye out for tigers that had been spotted a day or two before. The work
wasn’t quite done as we still had to carpet the new school computer room, so
after a hearty plate of Dal Bhat we set to it and finished around 2 am. The
final morning was another early one to catch the bus out of the village and
start the day long voyage along bumpy roads to Kathmandu. It was a really
productive time in the village enabling the Pico-Hydro team to get a better understanding
of the project landscape and to get to know the local villagers. Can’t wait to
get back out there and start the installation! - Jack
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