Together with Varun Beverages Zambia Ltd. we did a feasibility and amortization research for our photovoltaic milk cooling systems in Monze district in the south of Zambia.
In Southern Province and especially in Monze district the main income sources are small-scale farming and a bit of gardening (e.g. tomatoes, onions etc.). In case of small-scale farming, the revenues from sale of surplus yield (maize etc.) is more or less just 1 USD/ day per household.
Dairy farming, with an (initial) yield of around 10 l/ HH by average ( 2-3 l/ cow and 3-5 cows/HH) and revenues from sale of 3.20 K/ l (price paid by cooperatives to the dairy farmer), a HH can increase its income by average by 30 K/ day (3 USD).
VARUN has already started to establish diesel-run milk cooling plants in rural areas; up to now, there are 20 installed, 14 of them with cooperatives.
The alternative of a solar milk chiller should be of benefit for the dairy farmers, the cooperative and VARUN, i.e. to be at least of same benefit as the diesel-run system. In this context it has to be taken into consideration that the life-cycle costs of the solar chiller (over the period of 20 years) are lower than for the diesel-run alternative: The initial investment costs of the solar chiller are higher but this is by far over-compensated by saving the high operation costs of a fuel-run chiller.