| GATE - 1/88 - Micro-hydropower |
For almost a thousand years there were floating mills on the middle and lower reaches of European rivers. They were used for milling grain, pigments, powder etc., and later also for generating electricity. Bucket wheels raised the water to higher levels.
The river pump' is a development of this technology. While the floating mills had an undershot water wheel between two boats, which was set in motion by the river's current, the Issa Ber river pump has a current-driven propeller. Via a shaft and a cam, the propeller drives three reciprocating pumps which pump the water to the required level on the river bank. In order to compensate for changes in water level and keep the pump constantly in the area where the current is strongest, it is fixed beneath a float (raft) anchored in the river.
The Issa Ber river pump was designed to be suitable for average sized farms in many developing countries - that is, for families of ten to fifteen people, with one to two hectares of arable land. It makes it possible to irrigate all year round, even during the dry season. The pump is an ideal irrigation aid for growing vegetables - often a source of additional income for farmers, above all in the vicinity of towns and cities.
Local production possible
Right from the start, the pump was designed so that it could be produced in developing countries. The only equipment needed is a lathe, an electric drill and welding gear, plus of course a hammer, socket wrenches and so on.
(SchwimmkÃ¶rper = float; gelenk = joint; StrÃ¶mung = current; Propeller = propeller; 3 Zylinder 120° versetzt = 3 cylinders, offset 120°; Ansaugstutzen = intake pipe). The drawing is taken from the BORDA leaflet »FluÃŸpumpe 1984«
As the pumps are used on rivers they can be manufactured at a central riverside location when they are first introduced in a country. The river can then be used as a transport route.
However, since it is essential to provide a repair and maintenance service in the immediate vicinity of the users, village craftsmen must be trained for this purpose from the start. To prevent all the money from the villages finding its way into the towns and cities, it also makes sense to transfer production of the pumps to the villages as far as possible. If this can be done, the parts for which more complex machinery is needed (rotating parts) can be manufactured in a few larger towns, leaving the job of assembly to local craftsmen. This could also help slow down the exodus of craftsmen from the villages, by creating new potential sources of income locally.
More Cash for Environmental Tasks
In its latest annual report UNDP points out that voluntary contributions from governments received by the organization for its central resources, trust funds under its administration, and trough cost sharing, reached a record level of more than $1 billion in 1986. A similar result is expected for 1987.
The largest regional share of spending was in Asia and the Pacific, followed by Africa, Latin America and the Caribbean, and the Arab states. About 45 per cent went for international experts, approximately 24.1 per cent was spent on equipment and around 12 per cent went for training.
Advantages and limitations
With a diesel or electric pump water can be pumped anywhere, e. 9. from wells and ponds, too. With a river pump, on the other hand, pumping is only possible where the water is at least 1,5 m deep. In other words, the Issa Ber river pump cannot be used everywhere.
Also, in contrast to diesel or electric pumps, river pumps are subject to size limitations. The Issa Ber pump was deliberately developed specifically to meet the needs of farms with one to two hectares of land. Hence, large areas can only be irrigated by a corresponding number of pumps.
As regards their impact on national economies, river pumps can save the costs of imports and foreign currency, because they can be manufactured locally. As far as business economics are concerned, they only cost around half the price of an imported diesel pump, and energy costs (fuel oil) are eliminated altogether.