September 2008 Archives

To hear how the development of the water pump is coming along, watch my latest video blog from Mzuzu here:

I've spent the last couple of weeks sussing out the local suppliers (every other shop seems to be a hardware shop, which suits me!) and working out exactly what size system I should produce.

I have tried to assess the market, including the current demands and sources of water for the potential users. I have therefore toured the Land Management Department at the university, visited a couple of charities that install hand pumps around Mzuzu, The Agricultural Development Ministry, the Ministry for Irrigation and Water Development and the Rural Water Board.

So, after much consultation I believe the most appropriate solar pump would be one aimed at people looking for a step up from the hand pump, but who are unable or unwilling to pay the high running costs of the diesel and electric pumps on the market.

I have decided to test a range of configurations around a nominal system that would cost $700 and supply 8000 litres of water a day from a depth of 7m (the average well depth in Malawi). Although the initial capital cost is higher than existing diesel pumps (a comparable diesel pump costs around $300) there will be virtually no running costs for this solar pump and it would have a lifespan of around 15 years. When compared to a diesel pump producing the same amount of water, fuel and spares would require between $100-150 per year.

8000 litres a day is enough water for 80 inpatients at a hospital and would meet the domestic needs of about 250 people. It is also enough water for 120 cattle, or to irrigate enough land to feed one household of around six people.

65% of the cost of the solar pump goes on the solar panel, the cost of which drops every year, meaning that the pump will only become more competitive as fuel prices continue to rise.

I have also now ordered a motor and all the pump parts. Unfortunately that means that I have now reached the limit of the budget allocated to me by SolarAid and, ultimately, you!

It would be very useful to be able to try and test out different motors, for example the windscreen-wiper motor from a car. These motors are already mass produced and therefore will be considerably cheaper than the industrial motor I have bought in the UK. These other options are likely to be less efficient but I will only be able to find this out by testing them. I will only then be able to evaluate whether the money saved is worth it when compared to the increased size of solar panel needed.

Therefore, any donations made to the project now would potentially allow an even cheaper solar pump to be produced.

I have been very frugal with my budget so far and promise to make the most of any future donations.

Thank you,
Cai