This is an archival version of the original KnowledgePoint website.

Interactive features have been disabled and some pages and links have been removed.

Visit the new KnowledgePoint website at https://www.knowledgepoint.org.

 

Revision history [back]

click to hide/show revision 1
initial version
Neil Noble gravatar image
Energy

Referring back to an old publication Renewable Energy Technologies: Their Application in Developing Countries by L’A Kristoferson &V. Bokalders. It describes some simple do-it-yourself systems for solar water heating such as a black tray containing water and covered with water or black garden hose coiled up so that the water heats up as it passes through the hose. A more advanced form of integrated solar water heater consists of a black water tank inside an insulated box which has a glass wall to admit sunlight. These are sometimes called “breadbox” solar water heater. These would be a batch solar heaters which means that they are filled up with a quantity of water and then this water is heated up. I made of one of these in Botswana many years ago with an insulated body and simple collector. This design was an approach to simplify solar water heaters from the conventional design but was using similar materials such as the plastic and expanded foam.

There is a design of water heater at https://practicalaction.org/solar-energy-answers and one at WOT.

WOT - Werkgroep Ontwikkelingstechnieken, Working Group on Development Techniques
Vrijhof 205/206
P.O.Box 217
7500 AE Enschede
The Netherlands
Tel: +31 53 489 3845
Fax: +31 53 489 2671
e-mail: wot@tdg.utwente.nl
Website: https://www.wot.utwente.nl
A non-profit organisation working in the field of small scale sustainable energy, based at the University of Twente.

There is also a report on an interesting mobile design from South Africa in Boiling Point. Consumer response to mobile solar water heating in the low-income sector, South Africa https://www.nzdl.org/gsdlmod?e=d-00000-00---off-0fnl2.2--00-0----0-10-0---0---0direct-10---4-------0-1l--11-en-50---20-about---00-0-1-00-0--4----0-0-11-10-0utfZz-8-00&cl=CL3.28&d=HASHa0e7615639eed2c361a3f4.16&gt=1

But then you still have the issue of raising the water to the correct height. The only example I have seen was a small hand operated diaphragm pump that was used to pump water to an overhead tank for showers. The diaphragm pump can either be a single action diaphragm pump or a double action diaphragm pump. The technical brief https://practicalaction.org/human-powered-handpumps-for-water-lifting shows a single acting version. These pumps are good for low level lift by hand. One I looked at was £17 for a very small pump. Alternative low-cost pump options would include rope and washer style pumps which can be made locally. WOT has also been involved in Rope and Washer pumps.