The job is with Intermediate
Technology (IT) sometimes known as IT
development group (ITDG) who have offices in many countries including UK,
peru, sri lanka, zimbabwe, nepal... they operate on ethical principles,
centred around Schumacher's 'Buddhist economics' whereby local solutions
are found for local problems, and 'small is beautiful'. Nice people to
work for, in other words.
In this project they are
a small wind turbine for battery
charging (100 or 200 watts rating) which will be manufactured in Sri Lanka (and also Peru..). I am designing the alternator, and helping with other aspects. I produced
a design and built a prototype, took it out there and taught Udaya in his
small workshop how to build it. He built it and we tested it. It worked
fine and he was very enthusiastic to build many more. The blades etc are
still at the design stage. I understand from itdg that the whole project
will be put in the public domain when finished so that anyone can share it.
The funds come from UK government DFID.
ITDG Sri Lanka have done a
of successful small hydros for village
electrification, using induction motors and peltons in most cases.
Udaya Hettigoda, who I was teaching, had worked on 80 (or could he have said 18?) of such projects, and in some cases done the whole thing himself, from site assessment to designing/welding the manifold, building the electronic controller and commissioning the system. Now he is keen to build wind turbines.
Wind in SL is quite good in
but very seasonal. Between monsoons are
killer calm periods which cause a headache for system design. What to do
for power in these periods? Windpower is potentially very cheap, but if a
back up source is needed this can ruin the economics. If the back up is
PV, and sized to meet the load then it can run the load all year (no need
for windpower). Engine back-up is expensive.
IT took me to a site where they had a wind/Biogas system in operation. It's an interesting country to drive around in, to say the least.
The wind turbine was a 2kW unit
LMW in Holland. I know LMW well from
years gone by, so I was able to give some helpful practical advice. The machine was working quite well (to my surprise) on this site.
We took it down for some minor repairs and adjustments.
The thrust bush in the yaw head had worn out (nylon) and we replaced it with 3 brass washers, 100mm in diameter. This was fascinating mission, in a small agricultural town.
First we visited the machine
but they had no brass stock large enough (100mm diameter). Then we
some irrigation fittings in the scrap dealer which were
almost big enough. I was happy but the IT guys decided to check out the local store, and (miraculously) found a piece of brass stock of the right
size. You can buy anything at Embilipitya Stores!
But it cost 20,000 rupis
. A small fortune! In SL you can
buy a 4 hour train ticket for under a dollar, and raise a family on about
US$50 per month. Anyway we negotiated the price down by returning the
surplus, and had the washer machined. 2 hours skilled lathe work cost only
The biogas plant is a huge hole
the ground full of rice husk and manure
which lasts for 6 months. A big bell of steel captures the gas. There was
a small problem with the airfilter, so they were running the engine on dead
dynasaurs instead when I came. I hope they get that fixed. Biogas is
worth looking at for hybrid systems, but this system was very expensive, so
there is a way to go yet.
Sri Lanka people are very
always smiling, and a joy to be among. There
is an understandable desire to share the money which westerners bring into
the country. (Suddenly you find that you are fabulously rich compared to
the locals) and some are over-eager to provide you with services which you may
not need, but with good humour this need not be a problem. When they rock
their heads from side to side and say 'Ow ow' they mean 'yes', which is
rather hard to get used to, but very charming. I am looking forward to
going back next year if our plans materialise.